Se ean ee ee ee eee et SS ee EEE 
Appiendin: 397 
kind of infectious matter which assumes a tangible form, and can in 
that form be submitted to experiments; and which admits also of 
being afterwards tested by justifiable trials on healthy persons. Noth- 
ing presented itself to me, on consideration, so well adapted to fulfil 
all these conditions, as the matter of cow-pock. On mentioning my 
views to Mr. Roberton, one of the surgeons of the Manchester Ly- 
ing-in Hospital, he obligingly supplied me with vaccine lymph, taken 
from pustules of unequivocal character; and after the lymph had 
been subjected to high temperatures, he directed the insertion of it 
to be made, in the usual way, into the arms of healthy children. The 
trials were conducted, and the results registered, by Mr. Gee, the 
House-Apothecary of the Hospital. 
1. Vaccine lymph, dried at the temperature of the atmosphere on 
small bits of window-glass, was exposed to a heat of 180° Fahren- 
heit during four hours. ‘Three healthy children of proper age were 
inoculated with this matter without any effect ; but being afterwards 
vaccinated with fresh matter, they all took the disease. 
2. Lymph heated, during the same period, at a temperature vary- 
ing from 120° to 140°, generally 130°, was inserted without effect 
into the arms of two healthy children, who were afterwards success- 
fully vaccinated with recent matter. 
3. Four pieces of window glass, on which recent vaccine lymph 
was placed, were heated during intervals varying from two to three 
hours, at a temperature never below 160°, nor above 165° Fahren- 
heit. The trials were judiciously varied by Mr. Gee, by inserting 
each specimen of the matter which had been dried, into one arm 
only of a healthy child; while into the other arm of the same child 
recent matter was inserted. In every instance, the heated matter 
proved inefficient; while the matter which had been Wits the 
temperature of the atmosphere produced a satisfactory le. 
4. For the sake of obtaining a sufficient number of instances, I 
requested Mr, Marshden, House-Surgeon of the Manchester Royal 
Infirmary, to make trial of some genuine vaccine lymph which 1 had 
received from him, and had then submitted to heat. One specimen 
had been placed two hours in a steady temperature of 150°; a se- 
cond four hours in the same temperature ; a third two hours, and the 
fourth four hours, in the temperature of 172°. In no one instance, 
did any of these specimens, when inserted in the usual manner, pro- 
duce the vaccine pustule. : 
5. Descending in the scale of temperature, another portion of vac- 
cine lymph was exposed to an uniform heat of only 120° Fahrenheit 
. 
