4 Additional Notes. 



Not only microscopic animals appear to be produced by a sponta- 

 neous vital process, and then quickly improve by solitary generation 

 like the buds of trees, or like the polypus and aphis, but there is one 

 vegetable body, which appears to be produced by a spontaneous vital 

 process, and is believed to be propagated and enlarged in so short a 

 time by solitary generation as to become visible to the naked eye; I 

 mean the green matter first attended to by Dr. Priestley, and called 

 by him conferva fontinalis. The proofs, that this material is a ve^e- 

 table, are from its giving up so much oxygen, when exposed to the 

 sunshine, as it grows in Abater, and from its green colour. 



Dr. Ingenhouz asserts, that by filling a bottle with well-water, 

 and invei'ting it immediately into a basin of well-water, this green 

 vegetable is formed in great quantity; and he believes, that the water 

 itself, or some substance contained in the water, is converted into this 

 kind of vegetation, which then quickly propagates itself. 



M. Girtanner asserts, that this green vegetable matter is not pro- 

 duced by water and heat alone, but requires the sun's light for this 

 purpose, as he observed by many experiments, and thinks it arises 

 from decomposing water deprived of a part of its oxygen, and laughs 

 at Dr. Priestley for believing that the seeds of this conferva, and the 

 parents of microscopic animals, exist universally in the atmosphere, 

 and penetrate the sides of glass jars ; Philos. Magazine for May 1 800. 



Besides this green vegetable matter of Dr. Priestley, there is another 

 vegetable, the minute beginnings of the growth of which Mr. Ellis 

 observed by his microscope near the surface of all putrefying vege- 

 table or animal matter, which is the mucor or mouldiness; the vege- 

 tation of which was amazingly quick so as to be almost seen, and 

 soon became so large as to be visible to the naked eye. It is difficult 

 to conceive how the seeds of this mucor can float so universally in the 

 atmosphere as to fix itself on all putrid matter in all places. 



Theory of Spontaneous Vitality. 



IV. In animal nutrition the organic matter of the bodies of dead 

 animals, or vegetables, is taken into the stomach, and there suffers 



