44 ON THE IDENTITY OF SMALL-POX AND COW-POX. 
of the protective power of cow-pox against small-pox; and has an¬ 
nounced, we will venture to say, the most important discovery which 
has been made in the pathology of these diseases since vaccination 
was first introduced—by shewing that they are modifications of one 
another, and that cow-pox in the cow is simply small-pox in man, 
and may be produced in that animal at will by the variolous con¬ 
tagion. Of the authenticity of his facts we do not pretend to 
judge. All we can say is, that the author, if we judge from the 
language of Hufeland towards him, is a respectable practitioner, 
and a public medical officer. 
“ The simplest and surest mode,” says he, “ of producing cow- 
pox in the cow, and thus proving indisputably the identity be¬ 
tween the contagion of cow-pox and that of human small-pox, 
is to follow the procedure here laid down : — 
“Take a woollen bed-cover which has lain on the bed of a 
small-pox patient who has died during the suppurating stage, or 
is suffering from the disease in a considerable degree, and is lying 
in a small imperfectly-ventilated apartment, and when it is well 
penetrated by the contagion, roll it up immediately after death ; or 
on the fourteenth day of the disease, wrap it in a linen cloth, and 
then spread it for twenty-four hours on the back of a quey in such 
a manner that it cannot be thrown off by the animal. Then 
place it for twenty-four hours on the back of each of three other 
queys, and afterwards hang it in such a manner in their stall 
that its exhalations may rise upwards and be inhaled by them. 
In a few days the animals will fall sick and be seized with fever ; 
and on the fourth or fifth day the udders and other parts covered 
with hard skin will present an eruption of pustules, which assume 
the well-known appearance of cow-pox and become filled with 
lymph. This lymph, which exactly resembles the lymph of 
genuine cow-pox, if used for inoculating the human subject, will 
induce the vaccine or protective pock. The only precaution which 
it is necessary to observe is, that the person about to be inoculated 
shall not be exposed in any manner to the contagious effluvia of 
the cow-house, either directly or through the intervention of the 
experimentalist’s clothes, otherwise he may have natural small¬ 
pox. 
“ A bed-cover impregnated with the variolous contagion, if 
firmly rolled up and wrapped in linen, and afterwards in paper, 
and then properly packed in a bucket, will retain the contagion 
for at least two years, so as to infect a cow with cow-pox, pro¬ 
vided it be kept in a cool, shady place, where the temperature 
does not fall under thirty-two or above fifty-two degrees. 
“My present occupations prevent me, at this particular period, 
from giving a full and scientific exposition of the consequences 
