Sir,--As you have printed various letters on this important subject, perhaps you will kindly allow me to relate my experience.

    I may state that, like almost all opponents of vaccination, I was brought up a firm believer in it, but about 25 years ago I was induced to read some pamphlets against it which startled, but did not convince me. For the last 20 years I have given much attention to the whole question as a problem of statistics; I have read almost everything that has been written on both sides; I gave evidence before the Royal Commission in 1890; and I have carefully studied the reports of that Commission. In March last I published a small work dealing with the statistical evidence as given in these reports and in those of our Registrar-General, and I show that this evidence demonstrates the total uselessness of vaccination as a preventive or a mitigator of smallpox. The difficulty is to get people to give the time and attention necessary for a thorough mastery of the evidence. But I have already met with three cases in which strong believers in vaccination have given the necessary time and study to my book, and have in each instance become satisfied that the case against vaccination is so strong that Government is not justified in giving it either direct or indirect support.

    The assertion is continually made that statistics can be so treated as to prove anything, and that all statistical arguments are therefore untrustworthy. But this is wholly untrue, and no competent student doubts the value of statistical inquiry. Our whole insurance system is based on statistics, and almost all questions as to the national health as affected by locality, by occupations, and by other conditions, can only be answered by the use of those great bodies of national statistics--the Census reports and those of the Registrar-General. Such accurate statistics as these, dealing with great populations and extending over long periods of time, give the most accurate and trustworthy results. They really surpass all other kinds of evidence, inasmuch they furnish conclusions which approach very nearly to mathematical demonstration.

    But there is one thing essential in order to arrive at accurate conclusions from the study of statistics--the method of comparison. For example, suppose it to be asserted by teetotallers that abstinence from alcohol lengthens life; and they adduce as evidence certain communities--towns or villages or societies--in which abstinence has increased for the last 50 years, and show by statistics of death-rates in those communities that the average duration of life has steadily increased during the same period. But all your readers will see that these facts are nothing to the point, until you have compared these communities with others in which temperance or total abstinence has not increased, or very slightly so. If the comparison proves that these other communities also show the same improvement in life-duration, then it is clear that, so far as these statistics go, there is no proof of the beneficial results of abstinence.

    Now the case of vaccination and smallpox is exactly of the same nature as that above supposed. The fact that smallpox mortality has decreased during the period of vaccination is of itself no proof whatever of any cause and effect, unless it can be shown that there has been no corresponding decrease in other diseases during the same period, and for this purpose we must always compare smallpox mortality with total mortality and with that due to the other zymotic diseases.

    The main purpose of my little book, entitled "Vaccination a Delusion," is to make these comparisons and others of like nature--comparisons which the Royal Commissioners have not made, and the absence of which renders their conclusions worthless. I show that the great decrease of smallpox mortality during the present century, to which the writer of your article alludes, is not an isolated phenomenon due to a special cause--vaccination, but is a part of the general improvement in health due to a general cause--sanitation. During the 136 years from 1760 to 1896 the decrease (in London) of smallpox mortality, of the mortality from all other zymotics taken together, and of the total mortality, correspond very closely, and are represented on my diagram by three lines, which, with many irregularities, are yet generally parallel. For England and Wales during the period of accurate registration (1846-96) there is the same parallelism. In the Army and Navy, which, being wholly vaccinated, possess the utmost protection that vaccination can give, the total disease mortality has decreased as much as that from smallpox, and more regularly; while these highly-vaccinated forces have a smallpox death-rate about equal to that of the adult population of Ireland of the same ages, and more than double that of the town of Leicester, where vaccination has been continuously neglected for a quarter of a century, till now only 2 per cent. of the births are vaccinated!

    None of these comparisons have been made by the Royal Commissioners; and they demonstrate the very opposite conclusion to that which the Commissioners have arrived at--the total inefficacy of vaccination.

    I do not make these statements in order to initiate a discussion, which would be impossible within any reasonable limits, but for the purpose of making a proposal to any of your readers who may be disposed to give some time and trouble to the question, which is certainly a most important one. I shall be glad if any such person will call upon me, when I will lend him my book on the statistics of the question, Dr. Scott Tebb's recent volume on the history and medical aspects of vaccination, together with the full reports of the Royal Commission, by which almost all the facts adduced by myself can be tested.

    The work of Dr. Scott Tebb, though very full, is quite readable, and is a mine of accurate information on every aspect of the question. It is also of especial value and weight because the author, having been imbued with the traditions of his profession, was, till a few years ago, a believer in vaccination. But when it became a question of submitting his first child to the operation, he determined to investigate the whole subject for himself, with the result that he found the danger of vaccination to be so great and its benefits (if any) so infinitesimal, that he refused to have his child vaccinated, and has been duly summoned and fined by the Christchurch magistrates. It is clear that the evidence of an inquirer of this kind outweighs the belief, however positively stated, of any number of persons who have never given an hour's serious study to the question, but have merely adopted the opinions in which they have been educated. When we add that more than a dozen other medical men (several of them public vaccinators) gave evidence before the Royal Commission of the serious dangers of vaccination, and in several cases expressed their entire disbelief in its protective influence; that Dr. C. Creighton, the greatest authority on the history of epidemic diseases, and Professor Crookshank, equally eminent as an authority on animal diseases and Professor of Comparative Pathology and Bacteriology at King's College, both reject vaccination, as being utterly unscientific in theory, founded on erroneous observations, and having no value whatever as a preventive of smallpox; and when we further consider how painful and difficult it must have been for all these men, first to overcome the influence of their early teaching and prepossessions and then to set themselves in open opposition to their professional colleagues, with the certainty of being subjected to misrepresentation and abuse by parliamentary speakers and press writers, we may be sure that only the strongest conviction after the most thorough investigation could lead them to reject their early beliefs as altogether erroneous and to make their convictions public.

    If, therefore, we take these various facts into consideration it will be seen that the real weight, even of medical authority, may actually be greater on the side of anti-vaccinationists, although the great majority of the medical profession still loudly proclaim their belief in the value of the operation.