UTAH ACADEMY OF SCIENCES 71 
allowed to stand for a few days and then examined micro- 
scopically, millions of these micro-organisms were present. 
The theory of spontaneous generation was resurrected. I 
need not go into detail as to the arguments advanced and 
the experiments tried by its supporters, nor by those who 
defended the theory of biogenesis; suffice it to say, that the 
“Discontinuous Heating’ experiments of Tyndall gave the 
death-blow to the scientific heresy of ‘‘“Spontaneous Genera- 
tion”’. 
In the meantime, convinced that “all life comes from 
preceding life’, and therefore that bacteria could not be 
generated from the flesh of the body, the great Pasteur 
had begun his epoch-making discoveries. He had shown 
that fermentation is always caused by an organism; that 
the silkworm disease which in seventeen years in France 
had caused a loss of $250,000,000, and indeed even threat- 
ened the destruction of the industry, also was caused by 
a micro-organism, and that it could be absolutely prevented. 
He initiated the researches in the subject of serum therapy 
by developing sera for chicken cholera, anthrax and hydro- 
phobia. Commenting upon the results of Pasteur with 
the silk-worm disease, Huxley said in 1870: “There can be 
no reason, then, for doubting that, among insects, conta- 
gious and infectious diseases, of great malignity, are caused 
by minute organisms which are produced from pre-existing 
germs, or by homogenesis; and there is no reason, that I 
know of, for believing that what happens in insects may 
not take place in the highest animals. Indeed, there is 
already strong evidence that some diseases of an extremely 
malignant and fatal character to which man is subject, are 
as much the work of minute organisms as is the silk-worm 
malady’. Notice especially in this quotation the words 
“minute organisms that are produced from pre-existing 
germs.” The great stumbling block to the study of parasitic 
organisms had been removed. 
In England, also, the death of the Spontaneous Genera- 
tion theory had produced results; for Dr. Joseph Lister 
had reasoned that if putrefaction is always due to bacterial 
development, this must apply as well to living as to dead 
