GEOLOGY. 679 



live finds access, the learned of the eighteenth century ex- 

 plained the appearance of those innumerable swarms of 

 microscopic animals or plants which inevitably attack all 

 created things given up to putrid disorganization. 



Nothing could evade their terrible inroads. The won- 

 derful minuteness of these destructive agents allowed them 

 to clear all obstacles, and to insinuate themselves into the 

 most sheltered cavities ! Human intelligence was quite at 

 fault in attempting to penetrate into the secret of their 

 transmission through the most compact tissues of animals 

 and plants. 



In order the better to prop up their systems, at an epoch 

 when the talent of the orator was often substituted for real 

 learning, some of the philosophers attributed most paradox- 

 ical properties to these germs. It was as much as glass 

 could do to stay their invasion, or the hottest furnace to 

 consume them. Nothing arrested Bonnet on the subject of 

 these germs ; he believed that they resisted the most de- 

 structive chemical agents ; and even maintained that by 

 means of a circulation which was more than marvellous 

 they penetrated the entire economy of animated beings. 1 



1 " Every organized body," says Bonnet, " presents itself to me under the 

 image of a little earth, where I perceive in miniature all the species of plants and 

 animals which are found on a large scale on our globe. An oak appears to me 

 composed of plants, insects, shells, reptiles, fish, birds, quadrupeds, and even 

 men. I see innumerable germs rise into the roots with the juices designed for 

 their nutrition. I see them circulate in the different vessels and lodge in the 

 thickness of their membranes in order to augment their growth in every direction." 



Who would believe, then, that such a science found supporters in the nineteenth 

 century? Yet this has taken place. M. Le Vicomte Gaston d'Auvray, in order to 

 save from shipwreck the old doctrine of panspermism and the theories of M. Pas- 

 teur, has assumed that there exist in the air myriads of eggs and spores, the vital- 

 ity of which resists boiling for eight hours, and even a white heat. 



