174 LEISURE-TIME STUDIES. 



details will afford some idea of the method of procedure 

 adopted by experimenters, and of the care taken to ensure 

 the perfection of the rigorous conditions of isolation and 

 annihilation of any life contained in the substances infused. 

 It will thus be noted that, whilst negative results were 

 obtained in four out of the eight cases, three afforded 

 evidences of the production of living organisms in vacuo. 

 Dr. Burdon Sanderson, remarking on the results of these 

 experiments, says, "I am content to have established 

 at all events to my own satisfaction that by following Dr. 

 Bastian's directions, infusions can be prepared which are 

 not deprived, by an ebullition of from five to ten minutes, 

 of the faculty of undergoing those chemical changes which 

 are characterised by the presence of swarms of bacteria 

 (minute vegetable organisms), and that the development of 

 these organisms can proceed with the greatest activity in 

 hermetically sealed glass vessels from which almost the 

 whole of the air has been expelled by boiling." 



It is worthy of notice that these remarks contain a plain 

 statement of facts, without any indication as to their ex- 

 planation, or regarding the conclusions which may be drawn 

 from the results thus described. An impartial critic might 

 In such a case be ready with the query, Has the vital limit 

 of these lower organisms been ascertained ; or, is it deter- 

 mined as a stable and unquestionable fact that exposure to 

 the boiling point for five or ten minutes proves fatal to the 

 lowest forms of life ? Whilst it might also be asked whether 

 the appearance of living things in the closed vessels might 

 not be accounted for in the absence of any definite in- 

 formation negativing the supposition by presuming that 

 the vitality and development of the organisms contained in 

 the infusion had been simply suspended for a time by the 

 process of boiling. After a period of repose, when we may 

 presume their vital activities have recovered from the effects 

 of exposure to a high temperature, the organisms appear to 

 evince their wonted powers of development. 



The naturalist would inform such a critic, in answer to 



