ON EQUIVOCAL GENERATION. 121 



tcm of nature does not require an intelligent cause, neither 

 docs any other part, or the whole. 



As Dr. Darwin presses my observations on the green matter, 

 on which I formerly made some experiments, as producing 

 dephlogisticated air by the influence of light, into the service of 

 his hypothesis; I have this last summer given some attention to 

 them, and have diversified them with that view; and from 

 these it will appear that they are far from serving his purpose; 

 since none of this green matter, which he does not doubt to 

 be a vegetable, though of the smallest kind, is produced in 

 any water, though ever so proper for it, unless its surface has 

 been more or less exposed to the atmosphere, from which, 

 consequently, the invisible seeds of this vegetable may come. 



He says (Temple of Nature, notes p. i.J " not only mi- 

 " croscopic animals appear to be produced by a spontaneous 

 " vital process, and these quickly improve by solitary genera- 

 " tion, like the buds of trees, or like the polypus and aphis, 

 " but there is one vegetable body which appears to be produ- 

 " ced by a spontaneous vital process, and is believed to be 

 '* propagated and enlarged in so short a time by solitary gene- 

 " ration, as to become visible to the naked eye. I mean the 

 " green vegetable matter first attended to by Dr. Priestley, and 

 " called by him conferva jontinatis. The proofs that this material 

 " is a vegetable are from its giving up so much oxygen when 

 " exposed to the sun shine, as it grows in water, and from its 

 " green colour." 



" D. Ingenhouz asserts that by filling a bottle with well- 

 " water, and inverting it immediately into a bason of well- 

 " water, this green vegetable is formed in great quantity; 

 " and he believes that the water itself, or some substance con- 

 " taincd in the water, is converted into this kind of vegetation 

 " which then quickly propagates itself." 



" Mr. Girtanncr asserts that this green vegetable matter is 

 " not produced 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 he laughs at Dr. Priestley for be- 

 " lieving that the seeds of this conferva, and the parents of 



