124 



Dr. S. Monckton Copeman. 



[Nov. 13, 



disorder. On the other hand, this would hardly have been possible in 

 the case of persons contracting small-pox in the ordinary way, among 

 whom the disease was apt to exhibit such virulence as to account for 

 the death of perhaps 50 per cent, of those attacked. 



Not only were the effects following on inoculation comparatively 

 mild, but the disease in this form was intentionally brought into many 

 country districts which otherwise might not have become invaded by 

 small-pox. In the light of these facts, it has for some time past been 

 borne in upon my mind more and more convincingly that it was prob- 

 ably from the inoculated form of small-pox, rather than from the 

 ordinary variety of the malady, that much, at any rate, of the cow- 

 pox, in the pre- vaccination era, was derived. It is not difficult to 

 understand how that the cracks so often found on the udders of cows 

 might become infected by a milker with fingers contaminated by 

 contact with the inoculation sore upon his arm. 



I determined therefore, if possible, to put the matter to the test, 

 and, learning that in Nubia, in Burinah, and in certain parts of India 

 the inoculation of small-pox is still practised, I made numerous 

 endeavours to obtain the necessary material, but unfortunately without 

 success. 



In default, therefore, of inoculated small-pox in the human subject, 

 I made trial of the monkey, which, as I have shown in a previous 

 communication to the Eoyal Society, is readily susceptible to the 

 disease, the various phases of which in this animal closely resemble 

 those observed in man, but in a much milder form ; the occurrence of 

 a generalised eruption being exceptional. 



The different series of experiments, protocols of which I append, 

 have been carried out at intervals, determined mainly by the possi- 

 bility of procuring the necessary small-pox material. The work was 

 commenced in April, 1898, with a supply of small-pox lymph received 

 from the Medical Officer of Health for Middlesborough, in which town 

 an epidemic of the disease was then in progress. For subsequent 

 supplies I am indebted to the Medical Officer of Health and the 

 Medical Superintendent of the Small-pox Hospital at Glasgow, to the 

 Medical Superintendent of the West Ham Small-pox Hospital at 

 Dagenham, near London, and to the Medical Superintendent of the 

 Hospital Ships of the Metropolitan Asylums Board. 



The methods employed in the investigation have been briefly as 

 follows : — 



Collection of Material for Inoculation. 



In the first instance this was obtained in a manner similar to that 

 formerly employed in obtaining human vaccine lymph. Discrete 

 vesicles, mature, but still containing clear lymph, on one or another por- 

 tion of the body of a patient suffering from small-pox, were punctured 



