348 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



are also able to assimilate fixed combinations of albumen not 

 soluble in water, after they have previously rendered them 

 fluid, as is the case with hard-boiled egg, etc. This liquefac- 

 tion of solid or half-solid albuminous bodies, in combination 

 with their assimilation by Bacteria, and the concomitant pro- 

 duction of accessory matter, is generally termed putrefaction. 

 Sixth. The Bacteria are the only organisms which produce 

 putrefaction in albuminous substances. Seventh. As the ni- 

 trogenous food of Bacteria is consumed they gradually cease 

 to multiply, and pass from the movable to the quiescent con- 

 dition, during which they secrete an intercellular substance, 

 and heap this up into palmella-like masses (zooglcea). In this 

 state, however, they can still grow, and can again swarm out 

 under favorable circumstances. When all assimilable nutri- 

 ment is exhausted, these zooglcea masses settle to the bottom, 

 and the water again becomes clear. Mucous masses form 

 from these Bacteria, which are developed in moist air and 

 on nitrogenous soil, and usually produce, as accessory prod- 

 ucts, red, violet, yellow, green, and brown coloring matters. 

 Eighth. When water containing living Bacteria is evapora- 

 ted, innumerable Bacteria are discharged into the atmosphere, 

 principally as the smallest globular cells. The moisture pre- 

 cipitated from the air is filled with innumerable cells of this 

 kind, which are sometimes globular and sometimes cylindri- 

 cal. These are the germs of Bacteria, which are constantly 

 ascending into the air during the evaporation of putrefying 

 liquids, are inhaled into the lungs, are deposited with the rain 

 upon all bodies, and therefore are able to produce putrefac- 

 tion wherever they establish themselves. Their vitality is 

 not affected by their abode in the air, as is the case with some 

 of the infusoria, and the spores and gonidia of the fungi. 

 19 C, March 9, 1872, 8. 



RECENT OBSERVATIONS ON BACTERIA. 



As the result of still more recent researches in reference to 

 the Bacteria, especially in their relation to putrefaction and 

 contagion, Dr. Cohn informs us that the decomposition of bod- 

 ies not containing any nitrogen induced by microscopic organ- 

 isms we call fermentation, while an analogous decomposition 

 of nitrogenous, especially albuminous, substances is termed 

 putrefaction. The processes in the latter form of decomposi- 



