58 ORIGINATION OF LIVING BEINGS 



of minute tilings which could be obtained apparently 

 almost at will from decaying vegetable and animal forms. 

 Thus, if you took some ordinary black pepper or some 

 hay, and steeped it in water, you would find in the course 

 of a few days that the water had become impregnated with 

 an immense number of animalcules swimming about in all 

 directions. From facts of this kind naturalists were led to 

 ive the theory of spontaneous generation. They were 

 headed here by an English naturalist, Needham, and 

 afterwards in France by the learned BufTon. They said 

 that these things were absolutely begotten in the water of 

 the decaying substances out of which the infusion was 

 made. It did not matter whether you took animal or 

 vegetable matter, you had only to steep it in water and 

 expose it, and you would soon have plenty of animalcules. 

 They made an hypothesis about this which was a very fair 

 one. They said, this matter of the animal world, or of the 

 higher plants, appears to be dead, but in reality it has a 

 sort of dim life about it, which, if it is placed under fair 

 conditions, will cause it to break up into the forms of these 

 little animalcules, and they will go through their lives in 

 the same way as the animal or plant of which they once 

 formed a part. 



The question now became very hotly debated. Spal- 



lanzani, an Italian naturalist, took up opposite views to 



those of Needham and Buffon, and by means of certain 



xperiments he showed that it w r as quite possible to stop 



process by boiling the water, and closing the vessel in 



\\hich it was contained. "Oh!" said his opponents; 



" hut what do you know you may be doing when you heat 



the air over the water in this way ? You may be destroying 



son rty of the air requisite for the spontaneous 



n of the animalcules." 



< . Spaflanzani'i views were supposed to be upon 



le, and those of the others fell into discredit; 



pi though Uio fad was that Spallanzani had not made good 



\\V11. then, the subject continued to be revived 



i time to time, and experiments were made by several 



OH ; l>ut these experiments were not altogether satis- 



It \v;is found that if you put an infusion in which 



anii \\ould appear if it were exposed to the air into 



i.nii.-d it, and tin n sealed up the mouth of the 



! no air, save such as had been heated to 212, 



could rruch its contents, that then no animalcules would 



