More from the new issue of comedy journal Homeopathy. Homeopaths continue to pursue research on 'high dilutions' (i.e. dilutions such that there is highly unlikely to be any of the original solute remaining) in search of a vaguely plausible mechanism for homeopathy to work. Since the evidence is that homeopathy doesn't work, this is unlikely to be a fruitful endeavour, but it does provide entertainment for connoiseurs of pseudoscience.
The latest offering is a paper by one R. Assumpção , entitled "Electrical impedance and HV plasma images of high dilutions of sodium chloride" and an acccompanying editorial by Cyril Smith. Two sets of observations are presented: a set of Kirlian photographs and a set of measurements of the impedance of various homeopathic dilutions of NaCl.
What is Kirlian photography? When an object resting on a photographic plate is connected to a source of high voltage, an image is formed on the plate. Semyon Kirlian, whom the technique is named after, thought that such images might be compared to a human 'aura'. You can see how this would be attractive to various kinds of energy medicine fruitcakes. In the paper, Assumpção provides Kirlian photographs of homeopathic dilutions of an NaCl solution (6c, 12c, 24c and 30c) and of succussed (shaken) water without dilution. The images are certainly pretty, but what do they show? Not a lot, as far as I can tell. It isn't clear how such images should be interpreted, and all Assumpção really concludes is that different dilutions look different. This, in itself, is not a particularly exciting finding, in the absence of any hypothesis as to why that is and what it might mean.
What of the impedance data? Assumpção finds that impedance of the samples increases with dilution, up to about 12c (which is the point where Avogadro's constant suggests that there is unlikely to be any of the original NaCl remaining), and then decreases again slightly with further dilution. "This phenomenon is inexplicable in terms of conventional chemical theory" concludes Assumpção, a statement that really should be followed by "OMG!!!!11!1!1!!1!!!!!1".
Well, I think I have a reasonable explanation for the results that causes no problems for conventional chemical theory. As expected, dilution of the NaCl solution causes an increase in impedance as ions are removed from the solution. But there is also a competing increase in the concentration of dissolved ions caused by the succussion (agitation) process, as atmospheric gases and other impurities are dissolved in the water. So the small decrease in impedance beyond 12c could result from this process. I'm more puzzled as to why the impedance of the distilled water increases when it is shaken, suggesting a decrease in the concentration of dissolved ions. However, I suspect that there is a conventional explanation, but Assumpção doesn't seem to be particularly curious about this. Is there a change in the ionic species in the water as it is shaken? Does shaking facilitate outgassing of the dissolved gases that remain in the distilled water? We don't know. This continues the homeopathic water research tradition of publishing things without any thought as to what factors (other than the magic of water) might have led to the results.
Of course, the other thing to note is that the paper only looks at one solute, NaCl. For homeopathy, what would be really interesting is if you could show that there was a difference between two different homeopathic substances at dilutions greater than 12c. Previous attempts to do this have ended in some embarassment, as Smith acknowledges in the accompanying editorial, when he states "in the light of the controversy which has attended previous claims in this field, caution, and independent repetition of these results is required". There seems to be little sign of any such caution so far.
Finally, in Figure 5 of the paper, Assumpção had omitted to label to the impedance curves, showing which curve belongs to which dilution. The solution? Simply write the labels in, with a pen, afterwards. It is truly amateur hour.
Showing posts with label memory of water. Show all posts
Showing posts with label memory of water. Show all posts
Friday, 15 August 2008
Wednesday, 25 June 2008
More intention experiment: the ghost of Benveniste
I should probably avoid the Intention Experiment website, but it's such a fabulous compendium of nonsense and loony ideas that it's hard to leave alone. Now they're channeling the ghost of Jaques Benveniste. As many will know, Benveniste caused a storm of controversy when his lab published a paper in Nature that appeared to show that homeopathic concentrations of a certain type of antibody could have a biological effect, even though the chances of the solution containing any actual molecules of the antibody were tiny. This is the basis of the idea of 'memory of water' in homeopathy. The Nature paper was published with an unprecedented "editorial reservation", and a team assembled by Nature visited the Benveniste lab to look into the results. The results of the investigation were damning, showing that the design of the experiments was poor, and an article outlining the problems was published in a later issue of Nature. Ever since, homeopaths and other brands of quacks have been convinced that Benveniste's results were suppressed by the scientific establishment on behalf of Big Pharma, and so on.
Benveniste, however, was not put off by this setback, and continued in his work, going on to suggest that not only did the 'memory of water' effect exist, but that it could be transmitted digitally, down phone lines or over the internet. Brilliantly, this only gave 'positive' results when the equipment was being run by a particular researcher. Benveniste doesn't seem to have reflected too hard on why that might have been the case. Benveniste called this "digital biology", which would have "immense consequences on medical diagnostic procedures and the agro-food industry, with huge technological and commercial impact", and was only being held back because scientists are "opposed to the evolution of science". You recognise the narrative here, don't you?
Why do I mention all this? Because the Intention Experiment blog carries news of an experiment into "healing by e-mail". Apparently, a "Francesca McCarney, Ph.D., teacher of professional intuitives at the Academy of Intuitive Studies and Intuition Medicine" conducted the experiment, where 88 people were each sent 2 e-mails. One of these e-mails had "healing energy" "encapsulated" into it, and the other one did not. Apparently, the e-mails were indentified correctly 31.9% of the time, against a 25% probablity of getting them right by chance. This seems like a deeply unimpressive result, with no confidence interval to give us an idea of how likely it would be for such a result to occur by chance, but we're told that "scientists would consider it highly significant result" [sic]. We also don't know whether there might inadvertently have been clues in the text of the e-mails.
It seems that loony ideas never die; they just re-appear periodically in a slightly different form.
Benveniste, however, was not put off by this setback, and continued in his work, going on to suggest that not only did the 'memory of water' effect exist, but that it could be transmitted digitally, down phone lines or over the internet. Brilliantly, this only gave 'positive' results when the equipment was being run by a particular researcher. Benveniste doesn't seem to have reflected too hard on why that might have been the case. Benveniste called this "digital biology", which would have "immense consequences on medical diagnostic procedures and the agro-food industry, with huge technological and commercial impact", and was only being held back because scientists are "opposed to the evolution of science". You recognise the narrative here, don't you?
Why do I mention all this? Because the Intention Experiment blog carries news of an experiment into "healing by e-mail". Apparently, a "Francesca McCarney, Ph.D., teacher of professional intuitives at the Academy of Intuitive Studies and Intuition Medicine" conducted the experiment, where 88 people were each sent 2 e-mails. One of these e-mails had "healing energy" "encapsulated" into it, and the other one did not. Apparently, the e-mails were indentified correctly 31.9% of the time, against a 25% probablity of getting them right by chance. This seems like a deeply unimpressive result, with no confidence interval to give us an idea of how likely it would be for such a result to occur by chance, but we're told that "scientists would consider it highly significant result" [sic]. We also don't know whether there might inadvertently have been clues in the text of the e-mails.
It seems that loony ideas never die; they just re-appear periodically in a slightly different form.
Monday, 14 January 2008
Answer came there none...
More fall-out from the Homeopathy memory of water issue.
One of the papers in the Homeopathy special issue was by Rao et al., involving work by Rustum Roy, and had been touted around various places by Dana Ullman as evidence that homeopathy could work. The paper purported to use spectroscopic techniques to differentiate between homeopathic remedies, showing that there was some difference between them. It was fairly comprehensively taken apart by people at the JREF forums (including a minor contribution from me), and eventually a letter was submitted to the editor of Homeopathy outlining our concerns. This letter has now been published, alongside a response by Rao.
Hopefully, the other authors will forgive me if I summarise the points in the letter as follows:
1. The presented spectrum of pure ethanol looks nothing like ethanol of any recognised degree of purity.
2. There is no way of knowing whether the 'differences' between different preparations could have been caused by them being prepared with solvent containing different levels of impurities.
3. No statistical information was presented, meaning that no conclusions could be drawn as to whether the remedies were actually different.
4. Spectra that were supposedly representative of the tested preparations were actually the more extreme examples.
5. One graph was reproduced twice, purporting to show different things each time.
You'd imagine that all this was fairly damning, so how did the authors respond? On all of these points, answer came there none. Regarding the possibility of different levels of contamination between different samples, Rao simply says that this "illustrates one of the values of our work to homeopathy producers and users, and other health researchers. We have provided them with potential quality control tools, and a refining of the arguments away from incorrect generalizations". On the critical issue of contamination potentially invalidating the results of the paper, astoundingly, there is no comment.
On statistical analysis, Rao writes "All the analytical data shown in the paper are the result of reproducible analyses, although we appreciate the suggestion of representing such data as an average with a standard deviation, we emphasize that our key identification by display of an envelope demonstrates that, there are indeed differences beyond the standard deviation range among individual homeopathic remedies, as used in practice". What exactly the 'envelope' actually is has never been explained. It is certainly not a standard technique for statistical analysis. Without knowing what the standard deviation range actually is, it is impossible to demonstrate differences beyond it. While it could perhaps be argued that there are spectroscopic differences between 'homeopathic remedies, as used in practice', it can't be argued on this evidence that these differences are specifically related to the process of producing a homeopathic remedy, when different levels of different impurities can explain the results just as well.
Rao also states that s/he and her co-authors are "neither champions nor detractors of homeopathy". I'm not sure how this squares with co-author Rustum Roy showing up in the Grauniad to defend homeopathy.
On the other points, there is not a word. The authors have entirely failed to defend their work. I'm amazed. I thought there would be a more than cursory attempt to invalidate our criticisms, or at least clarify some of the ambiguities in the original paper.
I think that Rao et al. is dead, and in a sane world it would be withdrawn by the journal.
One of the papers in the Homeopathy special issue was by Rao et al., involving work by Rustum Roy, and had been touted around various places by Dana Ullman as evidence that homeopathy could work. The paper purported to use spectroscopic techniques to differentiate between homeopathic remedies, showing that there was some difference between them. It was fairly comprehensively taken apart by people at the JREF forums (including a minor contribution from me), and eventually a letter was submitted to the editor of Homeopathy outlining our concerns. This letter has now been published, alongside a response by Rao.
Hopefully, the other authors will forgive me if I summarise the points in the letter as follows:
1. The presented spectrum of pure ethanol looks nothing like ethanol of any recognised degree of purity.
2. There is no way of knowing whether the 'differences' between different preparations could have been caused by them being prepared with solvent containing different levels of impurities.
3. No statistical information was presented, meaning that no conclusions could be drawn as to whether the remedies were actually different.
4. Spectra that were supposedly representative of the tested preparations were actually the more extreme examples.
5. One graph was reproduced twice, purporting to show different things each time.
You'd imagine that all this was fairly damning, so how did the authors respond? On all of these points, answer came there none. Regarding the possibility of different levels of contamination between different samples, Rao simply says that this "illustrates one of the values of our work to homeopathy producers and users, and other health researchers. We have provided them with potential quality control tools, and a refining of the arguments away from incorrect generalizations". On the critical issue of contamination potentially invalidating the results of the paper, astoundingly, there is no comment.
On statistical analysis, Rao writes "All the analytical data shown in the paper are the result of reproducible analyses, although we appreciate the suggestion of representing such data as an average with a standard deviation, we emphasize that our key identification by display of an envelope demonstrates that, there are indeed differences beyond the standard deviation range among individual homeopathic remedies, as used in practice". What exactly the 'envelope' actually is has never been explained. It is certainly not a standard technique for statistical analysis. Without knowing what the standard deviation range actually is, it is impossible to demonstrate differences beyond it. While it could perhaps be argued that there are spectroscopic differences between 'homeopathic remedies, as used in practice', it can't be argued on this evidence that these differences are specifically related to the process of producing a homeopathic remedy, when different levels of different impurities can explain the results just as well.
Rao also states that s/he and her co-authors are "neither champions nor detractors of homeopathy". I'm not sure how this squares with co-author Rustum Roy showing up in the Grauniad to defend homeopathy.
On the other points, there is not a word. The authors have entirely failed to defend their work. I'm amazed. I thought there would be a more than cursory attempt to invalidate our criticisms, or at least clarify some of the ambiguities in the original paper.
I think that Rao et al. is dead, and in a sane world it would be withdrawn by the journal.
Sunday, 13 January 2008
Memory of water: Martin Chaplin's response
As any regular readers will no doubt be aware, there was a recent issue of the journal Homeopathy devoted to the concept of memory of water. Ben Goldacre put together a journal club on the issue. I ended up submitting a letter to the editor in response to Martin F Chaplin's paper 'The memory of water: an overview'. Essentially, I made the point that Chaplin's paper was interesting, but didn't really describe anything of relevance to homeopathy; and that, in any case, there was no observed effect of homeopathy that needed explaining. The letter has now been published, alongside Chaplin's response.
Chaplin writes that my argument 'fails on two levels; firstly such an argument [that there is evidence of water memory of relevance to homeopathic treatment] was not the primary purpose of my review and secondly, in fairness to its inclusion in the journal ‘Homeopathy’, I did present such an argument (e.g. Table 1, p. 149).' Let's leave aside for now that this seems to be saying both that he did not make such an argument and that he did. The first point is partly fair enough: it may be true that Chaplin's primary purpose was not to provide a justification for homeopathy. However, the paper was published in Homeopathy, which suggests some relevance to homeopathy. As to the second point, Chaplin's Table 1 doesn't really provide any argument, but simply lists some mechanisms by which water might have something that Chaplin terms a 'memory'. How these could actually apply in practice to homeopathy is not discussed, and none of them show how a homeopathic remedy would be any different from plain old water. That was the point of my letter.
In his final paragraph, Chaplin states that "It is clear from the final paragraph of the letter that its author has his own preconceptions concerning homeopathy and that he was disappointed that I was not able to reinforce these." This refers to my contention that meta-analyses of placebo-controlled trials show that the best-conducted trials show no effect for homeopathy above placebo, referencing as an example the Shang et al. meta-analysis that was published in the Lancet. That being the case, there is nothing in homeopathy that requires any explanation, whether from 'memory of water' or anything else. It is perhaps true that I have some pre-conceptions with respect to homeopathy: it is, after all, extremely implausible given what we know about chemistry, physics and pharmacology. However, my reference to meta-analyses of placebo-controlled trials is clearly a reference to evidence, and as such has nothing to do with 'pre-conceptions'. Chaplin's comment is therefore no more than an ad hominem.
Chaplin goes on to criticise the Shang et al. paper, referencing his website. The Shang paper is one that has been widely misunderstood homeopaths, as I've written previously. Chaplin makes some of the same errors. In his website he writes that "The conclusion [of Shang et al.] was reached, however, in spite of the study apparently showing little evidence of differences between the two groups (homeopathy and conventional) when all the data was considered. There were differences when a tiny percentage of unmatched larger trials were cherry-picked for further analysis (that is, 102/110 of the homeopathy studies and 104/110 of the conventional studies were discarded). The remaining 6% of the studies, however, still showed positive (if not conclusive, possibly as the number of trials left in this final grouping was so small) evidence in favour of a homeopathic effect over placebo." This is just a misunderstanding of the study. Shang et al. did indeed show an effect for homeopathy above placebo when considering the 110 homeopathy trials. But the trials were not 'cherry-picked' for further analysis. They were selected based on stated criteria, and based on the fact the analysis had shown that the best predictor of bias in the studies was study size. Shang et al. showed that when studies of inadequate methodology and studies with small sample sizes were stripped out, there was no statistically significant effect for homeopathy (contrary to Chaplin's assertion that there was positive evidence for an effect greater than placebo). I stand by my interpretation of the study, that it shows that 'the best-conducted trials show no effect for homeopathic remedies beyond placebo'.
On his website, Chaplin also seems to misunderstand the placebo effect, when he writes "It should also be noted that placebo effects constitute real clinical effects, should be judged positively and probably account for a significant proportion of the success of prevailing established medicine". The point here is that the placebo effect is what you get when you give patients a sugar pill containing no active ingredients. If a remedy produces an effect no greater than placebo, then why should it be judged more positively than a blank sugar pill? That's the whole point of conducting placebo-controlled trials!
Having read Chaplin's response, I see no reason not to stand by my original points. Firstly, that while Chaplin has shown that water is interesting stuff, he hasn't shown any water memory effect that could provide a mechanism for homeopathy to work. Secondly, the best evidence shows that homeopathy doesn't work and needs no explanation.
Chaplin writes that my argument 'fails on two levels; firstly such an argument [that there is evidence of water memory of relevance to homeopathic treatment] was not the primary purpose of my review and secondly, in fairness to its inclusion in the journal ‘Homeopathy’, I did present such an argument (e.g. Table 1, p. 149).' Let's leave aside for now that this seems to be saying both that he did not make such an argument and that he did. The first point is partly fair enough: it may be true that Chaplin's primary purpose was not to provide a justification for homeopathy. However, the paper was published in Homeopathy, which suggests some relevance to homeopathy. As to the second point, Chaplin's Table 1 doesn't really provide any argument, but simply lists some mechanisms by which water might have something that Chaplin terms a 'memory'. How these could actually apply in practice to homeopathy is not discussed, and none of them show how a homeopathic remedy would be any different from plain old water. That was the point of my letter.
In his final paragraph, Chaplin states that "It is clear from the final paragraph of the letter that its author has his own preconceptions concerning homeopathy and that he was disappointed that I was not able to reinforce these." This refers to my contention that meta-analyses of placebo-controlled trials show that the best-conducted trials show no effect for homeopathy above placebo, referencing as an example the Shang et al. meta-analysis that was published in the Lancet. That being the case, there is nothing in homeopathy that requires any explanation, whether from 'memory of water' or anything else. It is perhaps true that I have some pre-conceptions with respect to homeopathy: it is, after all, extremely implausible given what we know about chemistry, physics and pharmacology. However, my reference to meta-analyses of placebo-controlled trials is clearly a reference to evidence, and as such has nothing to do with 'pre-conceptions'. Chaplin's comment is therefore no more than an ad hominem.
Chaplin goes on to criticise the Shang et al. paper, referencing his website. The Shang paper is one that has been widely misunderstood homeopaths, as I've written previously. Chaplin makes some of the same errors. In his website he writes that "The conclusion [of Shang et al.] was reached, however, in spite of the study apparently showing little evidence of differences between the two groups (homeopathy and conventional) when all the data was considered. There were differences when a tiny percentage of unmatched larger trials were cherry-picked for further analysis (that is, 102/110 of the homeopathy studies and 104/110 of the conventional studies were discarded). The remaining 6% of the studies, however, still showed positive (if not conclusive, possibly as the number of trials left in this final grouping was so small) evidence in favour of a homeopathic effect over placebo." This is just a misunderstanding of the study. Shang et al. did indeed show an effect for homeopathy above placebo when considering the 110 homeopathy trials. But the trials were not 'cherry-picked' for further analysis. They were selected based on stated criteria, and based on the fact the analysis had shown that the best predictor of bias in the studies was study size. Shang et al. showed that when studies of inadequate methodology and studies with small sample sizes were stripped out, there was no statistically significant effect for homeopathy (contrary to Chaplin's assertion that there was positive evidence for an effect greater than placebo). I stand by my interpretation of the study, that it shows that 'the best-conducted trials show no effect for homeopathic remedies beyond placebo'.
On his website, Chaplin also seems to misunderstand the placebo effect, when he writes "It should also be noted that placebo effects constitute real clinical effects, should be judged positively and probably account for a significant proportion of the success of prevailing established medicine". The point here is that the placebo effect is what you get when you give patients a sugar pill containing no active ingredients. If a remedy produces an effect no greater than placebo, then why should it be judged more positively than a blank sugar pill? That's the whole point of conducting placebo-controlled trials!
Having read Chaplin's response, I see no reason not to stand by my original points. Firstly, that while Chaplin has shown that water is interesting stuff, he hasn't shown any water memory effect that could provide a mechanism for homeopathy to work. Secondly, the best evidence shows that homeopathy doesn't work and needs no explanation.
Tuesday, 13 November 2007
Still more on memory of water
An update on the fall-out from the special issue of the journal Homeopathy that was devoted to the 'memory of water'. This was written about extensively by me and many others, and in the end there was so much annoyance at what Philip Ball called an 'intellectual shambles' that a number of people have submitted letters to the journal's editor.
This morning I heard that my comments on Martin F Chaplin's article have been accepted for publication. The letter critiquing the Rao et al. paper that was jointly drafted by contributors to the JREF forums (I'm the third author) has also been accepted. Both should appear in the January issue of Homeopathy. So, to give the journal its due, it has not shied away from robust debate. This has doubled my publication record overnight, but I'm not sure if I should include these on my CV...
I expect that the authors of the original articles will have a reply published in the same issue. It will be interesting to see what they have to say.
Incidentally, an erratum to the Rao et al. paper has been published in the latest issue of Homeopathy. It deals with a referencing mistake, and is really the least of the problems with the paper, but it's something.
This morning I heard that my comments on Martin F Chaplin's article have been accepted for publication. The letter critiquing the Rao et al. paper that was jointly drafted by contributors to the JREF forums (I'm the third author) has also been accepted. Both should appear in the January issue of Homeopathy. So, to give the journal its due, it has not shied away from robust debate. This has doubled my publication record overnight, but I'm not sure if I should include these on my CV...
I expect that the authors of the original articles will have a reply published in the same issue. It will be interesting to see what they have to say.
Incidentally, an erratum to the Rao et al. paper has been published in the latest issue of Homeopathy. It deals with a referencing mistake, and is really the least of the problems with the paper, but it's something.
Wednesday, 19 September 2007
Even more on memory of water
I had a go at critiquing the recent Homeopathy special issue on the 'memory of water'. Ben Goldacre has now suggested that people who have been critiquing the issue could submit comments for publication to the journal. This is the way a civilised scientific debate is conducted, so I decided to give it a go. The following has been submitted as a letter to the editor (cheers to JJM and Rolfe at the JREF forums who proof-read it for me) :
Martin F. Chaplin presents an interesting overview on the structure of water1. Disappointingly, though, it seems to contain no useful evidence of a ‘water memory’ effect that would be relevant to the efficacy or otherwise of homeopathic treatments. As is well known, the probability of any dilution beyond about 12c (a dilution factor of 1x1024) containing a single molecule of the ‘mother tincture’ used to prepare the remedy is very low. So homeopaths require that water (or water/ethanol mixtures) somehow structurally ‘remember’ the mother tincture, and it is this structure that is responsible for any effect of homeopathic preparations. But Chaplin1 appears to be talking about an entirely different effect when he states that “If there is evidence that the history of a sample of water affects its properties, then the ‘memory of water’ concept is proven without the need for a rationale for its action” (p. 146). This apparently broad interpretation explains some of the examples given as “Evidence for the memory of water”, which otherwise appear to have little to do with homeopathic remedies, where the mother tincture must continue to influence water structure even when absent.
For example, Chaplin1 (p. 146) states that “human taste is quite capable of telling the difference between two glasses of water, processed in different ways (e.g. one fresh and one undrunk for several days)”. There is nothing mysterious about this. Depending on the circumstances, this can be due to outgassing of Cl2 and/or absorption of atmospheric CO2. This has nothing to do with how a mother tincture diluted out of existence has any effect on water structure. In the homeopathic context, what would be really interesting is if it were possible to taste the difference, say, between two 30c dilutions made from different mother tinctures prepared under identical conditions. Chaplin also refers to the Vybíral and Voráček paper in the special issue of Homeopathy2, stating that the authors “have shown that water changes its properties with time and its previous history”1 (p. 146). There is no doubt that this is an interesting paper, but the authors specifically conclude that their results are a consequence of ions dissolved in the water, as the effect they observe is not present when deionised water is used. Again, it is unclear how this is relevant to cases where mother tinctures are diluted out of existence. What Chaplin seems to be talking about in his paper is how impurities might affect water structure, as illustrated when he states “The water used for dilution is not pure relative to the putative concentration of the ‘active’ ingredient, with even the purest water considered grossly contaminated compared with the theoretical homeopathic dilution levels. This contamination may well have a major influence, and itself be influenced by the structuring in the water it encounters”1 (p. 148). Since the concentration of the mother tincture will always be dwarfed by the concentration of impurities, it is difficult to see why the mother tincture should have an effect more important than the impurities on the water structure. Homeopathic remedies are not ‘just water’: they will contain significant amounts of impurities, which might create interesting structures in the water. But how this would make them significantly different from any sample of water is not clear.
Martin F. Chaplin presents an interesting overview on the structure of water1. Disappointingly, though, it seems to contain no useful evidence of a ‘water memory’ effect that would be relevant to the efficacy or otherwise of homeopathic treatments. As is well known, the probability of any dilution beyond about 12c (a dilution factor of 1x1024) containing a single molecule of the ‘mother tincture’ used to prepare the remedy is very low. So homeopaths require that water (or water/ethanol mixtures) somehow structurally ‘remember’ the mother tincture, and it is this structure that is responsible for any effect of homeopathic preparations. But Chaplin1 appears to be talking about an entirely different effect when he states that “If there is evidence that the history of a sample of water affects its properties, then the ‘memory of water’ concept is proven without the need for a rationale for its action” (p. 146). This apparently broad interpretation explains some of the examples given as “Evidence for the memory of water”, which otherwise appear to have little to do with homeopathic remedies, where the mother tincture must continue to influence water structure even when absent.
For example, Chaplin1 (p. 146) states that “human taste is quite capable of telling the difference between two glasses of water, processed in different ways (e.g. one fresh and one undrunk for several days)”. There is nothing mysterious about this. Depending on the circumstances, this can be due to outgassing of Cl2 and/or absorption of atmospheric CO2. This has nothing to do with how a mother tincture diluted out of existence has any effect on water structure. In the homeopathic context, what would be really interesting is if it were possible to taste the difference, say, between two 30c dilutions made from different mother tinctures prepared under identical conditions. Chaplin also refers to the Vybíral and Voráček paper in the special issue of Homeopathy2, stating that the authors “have shown that water changes its properties with time and its previous history”1 (p. 146). There is no doubt that this is an interesting paper, but the authors specifically conclude that their results are a consequence of ions dissolved in the water, as the effect they observe is not present when deionised water is used. Again, it is unclear how this is relevant to cases where mother tinctures are diluted out of existence. What Chaplin seems to be talking about in his paper is how impurities might affect water structure, as illustrated when he states “The water used for dilution is not pure relative to the putative concentration of the ‘active’ ingredient, with even the purest water considered grossly contaminated compared with the theoretical homeopathic dilution levels. This contamination may well have a major influence, and itself be influenced by the structuring in the water it encounters”1 (p. 148). Since the concentration of the mother tincture will always be dwarfed by the concentration of impurities, it is difficult to see why the mother tincture should have an effect more important than the impurities on the water structure. Homeopathic remedies are not ‘just water’: they will contain significant amounts of impurities, which might create interesting structures in the water. But how this would make them significantly different from any sample of water is not clear.
- Chaplin, M.F. The memory of water: an overview. Homeopathy 2007; 96: 143-150
- Vybíral, B. and Voráček, P. Long term structural effects in water: autothixotropy of water and its hysteresis. Homeopathy 2007; 96: 183–188.
- Shang, A., Huwiler-Müntener, K., Nartey, L., Jüni, P., Dörig, S., Sterne, J.A.C., Pewsner, D., Egger, M. Are the clinical effects of homoeopathy placebo effects? Comparitive study of placebo-controlled trials of homoeopathy and allopathy. Lancet 2005; 366: 726-732.
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