SPONTANEOUS GENERATION. 567 
investigators. Its title was Heterogenie, and its author 
was F. A. Pouchet, director of the Museum of Natural 
History at Rouen. Ardent, laborious, learned, full not 
only of scientific but of metaphysical fervor, he threw 
his whole energy into the inquiry. Never did a subject 
require the exercise of the cold, critical faculty more than 
this oe calm study in the unraveling of complex phe- 
nomena, care in the preparation of experiments, care 
in their execution, skillful variation of conditions, and 
incessant questioning of results until repetition had placed 
them beyond doubt or question. To a man of Pouchet's 
temperament the subject was full of danger danger not 
lessened by the theoretic bias with which he approached it. 
This is revealed by the opening words of his preface: 
" Lorsque, par la meditation, il fut evident pour rnoi que 
la generation spontanee etait encore Tun des moyeus 
qu'emploie la nature pour la reproduction des etres, je 
m'appliquai a decouvrir par quels proceeds on pouvait 
parvenir a en mettre les pheuomenes en evidence." It is 
needless to say. that such a prepossession required a strong 
curb. Pouchet repeated the experiments of Schulze and 
Schwann with results diametrically opposed to theirs. He 
heaped experiment upon experiment and argument upon 
argument, spicing with the sarcasm of the advocate the 
logic of the man of science. In view of the multitudes 
required to produce the observed results, he ridiculed the 
assumption of atmospheric germs. This was one of his 
strongest points. " Si les Proto-organismes que nous voyons 
pulluler partout et dans tout, avaient leurs germes dis- 
setnines dans 1 'atmosphere, dans la proportion mathema- 
tiquement indispensable a cet effet, Fair en serait totalement 
obscurci, car ils devraient s'y trouver beaucoup plus eerres 
que les globules d'eau qui forment nos images epais. II 
n'y a pas la la moindre exageration." Recurring to the 
subject, he exclaims: "L'air clans lequel nous vivonsaurait 
presque la densitc du fer." There is often a virulent con- 
tagion in a confident tone, and this hardihood of argumen- 
tative assertion was sure to influence minds swayed not by 
knowledge, but by authority. Had Pouchet known that 
" the blue ethereal sky" is formed of suspended particles, 
through which the sun freely shines, he would hardly have 
ven tit red upon this line of argument. 
Pouchet's pursuit of this inquiry strengthened the con- 
