560 Abstract Report of Agricultural Discussions. 
of Kimbolton, Huntingdonshire, who in 1848 was his assistant, and 
who also wrote a letter, in 1862, to the public papers in support of the 
view which Mr. Kamsay had promulgated. Mr. Ramsay assumed 
that the reason why his vaccination succeeded was, that he had 
recourse to what in technical language is called retro -vaccination ; 
that is to say, he vaccinated a cow with vaccine lymph taken from 
the human subject, and, having obtained the produce of the lymph 
from the cow, he used it for operating upon sheep. With regard 
to retro-vaccination, I will only say that the experience of Mr. Cceley, 
Mr. Marson, and myself, is, that there is rather a loss both in the 
quantity and the quality of the lymph by retro-vaccination than a gain, 
and this opinion is supported by all continental authorities of any 
repute. If you take a quantity of lymph from the arm of a healthy 
child, and introduce it into a calf — as calves are more susceptible than 
cows — supposing it takes, you get very little, if any, increase of the 
material, and no greater activity of it. 
In 1848 I proposed to [Mr. Eamsay that he should allow some of 
the sheep which had been vaccinated on this plan to be subjected to 
the counter-proof of inoculation. Through the intervention of Mr. 
Ellis, of Triplow, in Cambridgeshire, Mr. Eamsay consented to select 
two sheep which he had vaccinated himself, and send them to me 
at the college. He did so, and wrote a letter to the ' Times ' in 
which he stated that he had sent two sheep to be tested as to the 
protective power of his vaccination. What was the result ? I took one 
of the sheep and inoculated it with some old sheep-pox virus which 
I had had by me for 16 weeks, during which time it might be 
supposed to have lost some of its power, and I readily produced the 
disease from it. The animal went through all the stages of the sheep- 
pox, and when it arrived at the vesicular stage I took lymph from this 
sheep and inoculated the other ; and with the same result. These 
two sheep were afterwards sent back to Mr. Ellis, who acknowledged 
the receipt of them. I wrote to Mr. Eamsay, saying that he was at 
liberty to test the sheep by any subsequent inoculation, or exposure 
to the disease, if he thought fit ; that they were not protected when 
they came to London, but were protected now. Yet, in the face of 
this fact, this gentleman again came before the public as an advocate 
for the vaccination of sheep in 1862. 
I trust that I have said sufficient to show that the agriculturist has 
been misled to some extent as to the effects of vaccination, and for this 
reason I think the Government deserves great credit for having deter- 
mined to test the tiling on a large scale. I would epitomise our own 
experiments by saying . that in every instance in which Mr. Marson 
and myself have been able to produce the vaccine disease in sheep, 
the animals, when exposed by us to natural small-pox, have taken it ; 
and in every case also in which wc have subjected sheep to the counter- 
proof of inoculation they have taken skeej>pox, and the disease has 
not been in the least degree mitigated by the previous vaccination. 
We have also found this very important fact — that whereas Messrs. 
Eamsay and Sprague speak as if the hundreds of sheep on which they 
operated were all successfully vaccinated, and as if every sheep was 
