1873O Atmospheric Life Germs. 231 



" The great interest of this method is, that it unques- 

 tionably proves that the origin of life in infusions which 

 have been boiled is solely due to solid particles suspended 

 in the air. Neither a gas, divers fluids, electricity, mag- 

 netism, ozone, things known or hidden causes, there is 

 absolutely nothing in ordinary atmospheric air which, fail- 

 ing these solid particles, can be the cause of the putre- 

 faction or fermentation of the liquids which we have 

 studied." It has so far been definitely proved by Pasteur, 

 and stated in the following manner ; — 



" 1st. That there are constantly, in ordinary air, or- 

 ganised particles which cannot be distinguished from the 

 true germs of the organisms found in infusions. 



" 2nd. When these particles and the amorphous debris 

 associated with them are sown in liquids, which have been 

 previously boiled and which remained unchanged in air pre- 

 viously heated, there appear in these liquids exactly the 

 same forms of life as arise in them when they are exposed 

 to the open air." 



" Such being the case, could a partisan of spontaneous 

 generation wish to uphold his principles even in the face of 

 this double proposition ? He might, but then his argument 

 would necessarily be of the following kind, of which I leave 

 the reader to judge for himself. There are in the air, he 

 might say, solid particles, such as carbonate of lime, silica, 

 soot, fibres of linen, wool, and cotton, starch granules . . . 

 and besides these organised corpuscles having a perfect re- 

 semblance to the spores of the Mucedineas or the germs of 

 Infusoria. I prefer to attribute the origin of Mucedineae and 

 Infusoria to the first amorphous substances rather than to 

 the second." 



This has actually been asserted. Could there be more 

 eccentric reasoning ? Reasoning it is not. That question 

 is beyond the pale of argument, to which common sense 

 dictates the answer. 



It is not exactly true that the smallest quantity of ordinary Air 

 gives rise in an Infusion to the Organisms peculiar to this 

 Infusion. Experiments on the Air of various Localities. 

 Inconvenience of employing Mercury in Experiments relative 

 to Spontaneous Generation. 

 If the smallest quantity of air in contact with an infusion 

 gives rise to organisms, and these organisms are not of 

 spontaneous origin, then it follows that in the minute por- 

 tion of air there must exist a multitude of the germs of very 

 different organisms ; in such numbers, too, that, as Pouchet 



