314 THE MICROSCOPE AND ITS REVELATIONS. 



Lister, Tyndall, and others, seem to the writer to leave no reasonable 

 doubt on these two points (1) that putrefactive fermentation does not 

 take place, even in liquids which are peculiarly disposed to pass into it, 

 except in the presence of Bacteria-germs; and (2) that neither these 

 germs, nor any others, arise in such liquids de novo, but that they are all 

 conveyed into them by the air, when not otherwise introduced. "Whether 

 there are different species of Bacteria, Bacillus, etc., which (as main- 

 tained by some) excite distinct forms of disease respectively peculiar to 

 them, in the bodies of animals into which they find their way, is a ques- 

 tion which he thinks is scarcely yet ripe for decision. Strong evidence 

 in its favor is afforded by the facts now accumulated in regard to the 

 transmission of special forms of disease by inoculation, in some instances 

 with Bacillus germs, and in others with very minute germinal particles 

 termed microzymes, whose nature is still unknown. Thus ( splenic fever ' 

 is producible by the inoculation of Bacillus anthracis, and the typhoid 

 fever of the pig by inoculation with another species of Bacillus j 1 the 

 plants having been in both cases ( cultivated,' so as to be free from other 

 contaminating matter. Again, it has been ascertained by careful micro- 

 scopical examination of the fluid of the Vaccine vesicle, that it is charged 

 with a multitude of minute granules not above 1-20, 000th of an inch in 

 -diameter; and it has been further determined that these, rather than the 

 iluid in which they are suspended, are the active agents in the produc- 

 tion of a similar vesicle in the skin into which they are inserted. This 

 vesicle must contain hundreds or thousands of 'mierozymes' for every 

 one originally introduced; and it is obvious that their multiplication has 

 so strong an analogy to that of Bacteria, as to suggest the idea that it 

 must take place by a like process of cell-development. Similar observa- 

 tions have been made upon Glanders, Sheep-pox, and Cattle plague; so 

 that an animal suffering under either of these terrible diseases is a focus 

 of infection to others, for precisely the same reason that a tub of ferment- 

 are those in which the careful filtration of the air (as by simply plugging the 

 mouth of the tube or flask with cotton-wool), or its purification by the subsi- 

 dence of the minute particles it ordinarily holds in suspension (as demonstrated 

 by Prof. Tyndall's optical test), prevents any putrefactive change from taking 



reprinted in his " Critiques 

 and Addresses;" Prof. Lister on 'Bacteria and the Germ-theory,' in " Quart. 

 Journ. of Microsc. Science," Vol. xiii., p. 380, on 'The Nature of Fermentation' 

 in vol. xviii. of the same Journal, p. 177, and his Address to the British Medical 

 Association at Cambridge, in * Brit. Med. Journ.,' 1880, p. 363; and Prof. Tyndall 

 on ' The Optical Deportment of the Atmosphere in Relation to the Phenomena of 

 Putrefaction and Infection,' in "Philos. Transact.," 1876, p. 27, and 'Further 

 Researches' in " Philos. Trans.," 1877, p. 149; also, for an account of recent 

 Pathological researches by Pasteur and others, 'Journ. of Roy. Microsc. Soc.,' 

 vol. iii. (1880), pp. 1006-1020. The doctrines advanced on the other side in Dr. H. 

 Charlton Bastian's ''Beginnings of Life," do not, in his judgment, stand the test 

 of rigid scrutiny. 



1 The dried blood of horses that had died in India of 'Loodiana fever,' having 

 been sent to the Brown Institution, a crop of Bacillus anthracis was grown from 

 it, which reproduced the disease in healthy animals. The very important fact 

 has been discovered at the same institution, that the ' brewers' grains ' largely 

 used as food for cattle, afford a soil which is peculiarly favorable for the growth 

 and development of the spore-filaments of Bacillus; and thus an obvious explana- 

 tion was given of an epidemic of anthrax in a previously uninfected district, 

 destroying a large number of animals, all of which had been fed with ' grains ' 

 obtained from a particular brewery. 



