2 SCIENCE PROGRESS 
experiment was guided by reasoning from entirely erroneous 
premisses. For a long time subsequently, knowledge was 
greatly advanced by descriptive investigations undertaken with 
the assistance of the microscope. Later, experiment was 
resorted to again, in applying the methods of bacteriology, 
with results which showed rather what cancer was not, than 
what cancer was. Biological knowledge required to advance 
in other fields before the experimental method could be so 
applied to the study of cancer as to yield positive contributions, 
carrying us forward from where clinical, histological, and 
bacteriological studies had reached their limitations, and from 
where physiology and chemistry could find no point of attack. 
The Academy of Sciences, Belles Lettres, and Arts at Lyons 
proposed the following as the subject of a prize dissertation 
for the year 1773: “To form such inquiries on the causes 
of the cancerous virus as may lead us to ascertain its nature and 
effects, and best methods of obviating it.” The foul sloughy 
discharge, the ‘‘cancerous virus,” proceeding from ulcerating, 
septic, ‘‘ open cancers,” was at that time held to be the character- 
istic of the disease, and the subject selected was the direct 
incentive to the first experiment on cancer. 
The prize was awarded to Bernard Peyrilhe, who remarks, 
in the course of his essay, ‘‘With respect to the contagious 
nature of this virus, it must be acknowledged that, either exter- 
nally or internally applied, itis capable of infecting the healthiest 
of men.” ... He found that by the subcutaneous injection of 
what he regarded as the “cancerous virus,” he could reproduce 
those clinical features which were at the time supposed to be 
characteristic of the disease. The correspondence seemed to 
him, and to the judges of the prize, to be so close as to merit 
the inference that he had communicated cancer itself, although 
the experiment terminated prematurely. His essay was ordered 
to be published bythe Academy. It attracted so much attention 
that it was translated into various languages, and influenced 
medical opinion for many years. The experiment really bore 
on the transference of secondary bacterial infections, and not 
on the transference of cancer. The experimental investigation 
of cancer is to-day something entirely different. The sine gua 
non to its satisfactory pursuit is the fulfilment of the require- 
ments insuring absolute asepsis. The animals which are made 
to bear cancerous growths artificially, suffer little or no incon- 
