INFUSORIAL ANIMALCULES. 27 



In some recent experiments, Ehronberg has observed, that living 

 siliceous Infusoria form a sort of moist earth, (humus) and need a 

 very small quantity of water to sustain life ; and that even when 

 such humus was let diy fifteen days, a great number still remained 

 alive, and became very active on being inti'oduced into a drop of 

 water. If the earth was perfectly dried, they died outright, becoming 

 incapable of revivification. 



According to M. Doyere's experiments (Ray Society, 1841) Rota- 

 toria may be completely dried in pure sand, in the open air, in dry 

 air, and in a vacuum, without losing the capability of being revived 

 by moistiu'e. 



Section IX. — On the Siqyposed Metliod of Manufacturing Infusoria. 

 — "Within the last few years an idea has been prevalent, and many 

 persons have occupied themselves in endeavouring to realize so extra- 

 ordinary a discovery, that animal life may be produced by means of 

 galvanism. The creatures said to have been thus brought into exist- 

 ence, that have come under my observation, were neither the most 

 minute, nor the most simple, in organization ; and evidently 

 belonged to the class Acari. That many scientific men should be 

 more than sceptical upon this point, cannot be wondered at ; and 

 were it not that the notion originated with, and the experiments 

 have been conducted by, one who holds a most honourable position 

 amongst us, it would not have been entertained for a moment. That 

 some mistake exists with respect to communicatiag vitality to matter, 

 by this means, there cannot be a doubt. 



It is not surprising that Linneus, with the imjierfect microscopes 

 of his day, should mistake Infusorial Animalcules for minute drops 

 of oil in the water; but that Dutrochet, so late as 1833, should 

 publish to the world that aU the globular and elliptical Infusoria 

 were vesicles set in motion by streams of electricity, and therefore 

 could be artificially produced, is but another exemplification of the 

 fact, that men of the most distinguished talents in one department 

 of science may form very eiToneous notions on others, especially 

 where long contiimed observations, and very acciu-ate perceptions, 

 are indispensable for arriving at right conclusions respecting them. 



In 1834, Cagniard Latour made a public declaration, that he had 

 manufactured animalcules by the aid of carburetted hydrogen. This 



