156 CATHOLIC WRITERS AND 



in various universities, logic, metaphysics, Greek, 

 and finally natural history. He first explained 

 the physics of what children call " ducks and 

 drakes " made by flat pebbles on water ; laid the 

 foundations of meteorology and vulcanology, and 

 is perhaps best of all known in connection with 

 what is termed " regeneration " in the earthworm 

 and above all in the salamander. His experi- 

 ments still hold the field in a region of study 

 which has vastly extended itself in recent years, 

 becoming of prime importance in the vitalistic 

 controversy. 



In the dispute, however, with which we are 

 concerned Needham and Spallanzani defended 

 opposite positions. The former, as the result of 

 his observations, asserted that, in spite of the 

 boiling and sealing up of organic fluids, life did 

 appear in them. His opponent claimed that 

 Needham's experiments had not been sufficiently 

 precise. The latter had enclosed his fluids in 

 bottles fitted with ordinary corks, covered with 

 mastic varnish, whilst Spallanzani, employing 

 flasks with long necks which he could and did 

 seal by heat when the contents were boiling, 

 showed that in that case no life was produced. 

 He declared, and correctly too, as we now know, 

 that Needham's methods did permit of the intro- 

 duction of something from without. The con- 

 troversy went to sleep again until the discovery 

 of oxygen by Priestley in 1774. When it had been 

 shown that oxygen was essential to the existence 

 of all forms of life, the question arose as to whether 

 the boiling of the organic fluids in the earlier 



