ATMOSPHERE IN RELATION TO PITTREFA CTION AND INFECTION. 
59 
Still the deportment of the hare-infusion may have been due, not to any specific 
difference between hare and pheasant, but to the circumstances preceding death. The 
researches of Dr. Brown-Sequard show that even the same animal tissue exhibits, under 
different circumstances, very different tendencies to putrefaction. In guinea-pigs sub- 
jected immediately after death to the action of the magneto-electric current, he found 
the rapidity of putrefaction to correspond with the violence of the tetanization. He 
also draws attention to the influence of muscular exercise on cadaveric rigidity and 
putrefaction, showing how quickly they appear in “overdriven cattle and in animals hunted 
to death.” It is known, indeed, to sportsmen that a shot hare will remain soft and limp 
for a day, while a hunted one becomes rigid in an hour or two. In September 1851 two 
sheep which had been overdriven to reach a fair were killed by the section of the 
carotid arteries. “ Putrefaction,” says Dr. Brown-Sequard, “ was manifest before the 
end of the day, or in less than eight hours after death”*. The deportment of the hare 
operated upon by me may therefore depend upon the circumstance of its being brought 
down by the greyhound instead of the gun. It will be interesting to inquire how far 
the peculiarity of the animal tissue is transferred to the infusion. This is a subject for 
further investigationf . 
Such observations inculcate caution in drawing inferences from the deportment of any 
infusion as to the distribution of germs in the air. The germs may be demonstrably 
present while the infusion may not favour their development. As to the quantity of 
atmospheric germs, the hare and the pheasant might lead to different conclusions. A 
passing reference to an important practical inference may be fitly introduced here. In 
one of the earliest of the able series of researches with which he has enriched medical 
science, Dr. Burdon Sanderson exposed to the air “Pasteur’s solution,” which is capable 
of vigorously developing and nourishing Bacteria when they are communicated to it by 
inoculation ; he also permitted air to bubble through the liquid, and finding no deve- 
lopment in either case he inferred the entire absence of Bacteria and their germs from 
the air, considering water to be their exclusive habitation. Other distinguished men have 
come to the same conclusion ; while in his books and papers, and in the discussion before 
the Pathological Society already referred to, Dr. Bastian has forcibly dwelt upon the result 
as justifying the interpretation which he has affixed to his experiments. If, he rightly 
urges, the air be “ entirely free ” from matter which could produce Bacteria , then their 
appearance in boiled infusions exposed to the air must be due, not to any thing contained 
in the air, but to the inherent power of the infusions. Spontaneous generation is 
undoubtedly the logical outcome of the position that “ the germinal manner from which 
* Croonian Lecture, Proe. Roy. Soc. 1862, vol. xi. p. 210. 
f Five and twenty flasks containing pheasant-infusion were compared during the month of December with 
five and twenty containing infusion of hare. Neither in the rapidity of Bacterial development, nor in the 
readiness to support the growth of Penicillium, did the considerable differences between hare and pheasant first 
observed repeat themselves. 
MDCCCLXXVI. 
E 
