SPONTANEOUS GENERATION. 327 



It was not till the earth's crust had so far cooled that the 

 water had condensed into a fluid form, it was not till the 

 hitherto dry crust of the earth had for the first time become 

 covered with liquid water, that the origin of the first 

 organisms could take place. For all animals and all plants — 

 in fact, all organisms — consist in great measure of fluid 

 water, which combines in a peculiar manner with other sub- 

 stances, and brings them into a semi-fluid state of aggrega- 

 tion. We can therefore, from these general outlines of the 

 inorganic history of the earth's crust, deduce the important 

 fact, that at a certain definite time life had its beginning on 

 earth, and that terrestrial organisms did not exist from 

 eternity, but at a certain period came into existence for the 

 first time. 



Now, how are we to conceive of this origin of the first 

 organisms ? This is the point at which most naturalists, 

 even at the present day, are inclined to give up the attempt 

 at natural explanation, and take refuge in the miracle of an 

 inconceivable creation. In doing so, as has already been re- 

 marked, they quit the domain of scientific knowledge, and 

 renounce all further insight into the eternal laws which have 

 determined nature's history. But before despondingly taking 

 such a step, and before we despair of the possibility of 

 any knowledge of tliis important process, we may at least 

 make an attempt to understand it. Let us see if in reality 

 the origin of a first organism out of inorganic matter, the 

 origin of a living body out of lifeless matter, is so utterly 

 inconceivable and beyond all experience. In one word, let 

 us examine the question of spontaneous generation, or archi- 

 gony. In so doing, it is above aU things necessary to form 

 a clear idea of the principal properties of the two chief 



