WCP3042

[1]

28 Great Ormond St. London W.C.

2^nd. August 1889

My dear Sir

I find it not easy to deal with your very legitimate inquiry about the alleged immunity. It occurs to me, however, that you might give the generally accepted medical doctrine a fairer chance by taking the endemic London smallpox of last century. I enclose the figures, & shd be glad to have the paper back some time, as I have no copy. The cases would be, on a fair average, six times the deaths. The population of London in these years, I have not the means at hand of ascertaining.

[2] Your explanations (a | b | c | d) are reasonable in kind — I am not clear that they are not controvertible here & there. I used much the same arguments in dealing with whooping-cough in a recent book — having a decided opinion that it differs from the diseases with which it is usually classed in fundamental respects.

I cannot help thinking that we have reason for the empirical teaching that one attack of smallpox finds a physiological immunity. Even in Africa, where negroes [3] brats & others are almost constantly exposed, it attacks once, and is then done with. In the passage marked in the Address which I send, I endeavoured to give an explanation of the immunity b ^from smallpox, in contrast to the [illeg.] to repeated attacks of other skin diseases. I join the acquisition of specific character to the habit of the disease attacking only once.

It is not easy to say how large a proportion the exceptions are. In a letter of Jenner¹ to Miss Calcraft² 19^th June, 1811 he says: "the cowpox must possess preternatural powers if it would give uniform security to the constitution, when it is well [4] known that smallpox cannot; for we have more than one thousand cases to ^prove the contrary, and fortunately seventeen of them in the families of the nobility.”³

I suspect there were in great part cases of bogus inoculations of smallpox — of very different insignificance from full eruptions of the disease on the skin.

In any case, we ought I think, to land upon the fact that a cowpox is not smallpox in any conceivable sense. Doubtless it was accepted as such at the outset, Jenner having managed to trick the profession. Whatever be the value of the immunity doctrine in general, cowpox against smallpox does not come under the head of Dr. Jenner,

dear Sir, yours sincerely | C. Creighton⁴ [signature]