hearing on Spontaneous Generation. 181 



are living they would be destroyed by this corrosive, and if pro- 

 duced out of the inorganic C H N of the tartarate, they might 

 still arise by spontaneous evolution ; as all the corrosive sublimate 

 was again removed by precipitation by the iodide. 



In the case of the distilled water solution, if the filaments arise 

 out of the inorganic C H N, here was an opportimity for that to 

 take place. But we find no change, as there were no germs in the 

 water, none in the salt, and no air for them to arise from. 



In the experiment with citric acid, the mucedo is formed in 

 spite of the Condy's fluid ; which at once indicates that this disin- 

 fectant is not fatal to aU forms of protozoal hfe. In 1866 I found 

 that neither Baphnia pulex, the larvae of gnats, nor minnows, were 

 at all inconvenienced by Condy's fluid, while carboMc acid speedily 

 knied them aU. 



The experiment with the liver of a rat seems to show that 

 cotton-wool is not a safe protector against " germs " ! ! 



As one who has looked anxiously for motion as a sign of life in 

 the " pin-point " monads, especially as distinct from the current and 

 Brownian movements of inorganic particles, I cannot but feel much 

 sympathy with the remarks in this Journal of Feb., 1871, pp. 81-2, 

 ** On Motion in Microscopic Granules," quoted from C. S., in the 

 Boston Journal of Chemistry. The remarks in Professor Frank- 

 land's paper in * Nature,' Jan. 19, 1871, " On the Movements of the 

 Dumb-bell," particles of glass (which might have led to error in less 

 experienced hands than those with whom he was associated) show 

 how necessary it is to be cautious in minute examinations, I have 

 myself called attention, in a note, ' M. M. J.,' April, 1870, p. 200, to 

 the movements of sodium on water when ignited, which resemble 

 those of some forms of monads. I would venture to suggest that 

 when movements of a particle or object are referred to as a proof of 

 vitality, some detail of description should be given as to the modes 

 in which such movements occur. 



As a rule there is much difference between the cyclical move- 

 ment of a smaU monad, and the slow, irregular, jerking movement 

 of particles, which is due to evaporation of the Hquid, and the 

 regular, synchronous, and si mi 1 ar • direction-movements of particles 

 in a current, or those movements which are seen in exaraining 

 infusions, and produced by the action of some moving animalcule 

 which is outside the field of view. 



o 2 



