4 DEPJVATION OF ORG.VNIC BEI^^GS. 



paratus was immediately sealed hermetically ; but, notwith- 

 standing these precautions, Infusoria were soon developed 

 in the contained fluid. To the cogency of these experi- 

 ments, Milne Edwards takes objection on the following 

 grounds : — 



1. The inadequacy of the means employed to ensure the 

 heating of the whole mass of hay to the boiling point, or to 

 any temperature inconsistent with the retention of vitality. 



2. The capacity of animals, such as the Rotifera — much 

 higher in the scale than the simpler Infusoria — of recovering 

 their vitality on being moistened after desiccation, and even 

 after exposure in the dry state, to a degree of heat which 

 would be fatal in the natural condition.* 



Dr. Daubeny's experiments were of the same general 

 nature as those of Schultze. No development of animal 

 life took place ; but, notwithstanding all the precautions 

 employed, mouldy vegetations made their appearance in 

 the fluid. In the discussion which ensued on the reading 

 of Dr. Daubeny's paper, tv>^o possible sources of fallacy were 

 suggested — the employment of lint-seed meal luting, and 

 the passage of the air through the oil of vitriol in bubbles 

 of too laro'e a size to ensure the full action of the caustic 

 on all the suspended particles of an organic nature. But, 

 as far as concerns the mucedinous Fungi, which give origin 

 to these vegetations, it would appear that sulphuric acid, 

 however employed, is no real barrier ; for M. Pasteur has 

 found that they will bear even the prolonged contact of the 

 concentrated acid without losing their power of germination.-f* 



The experiments of M. Pasteur, in some other points 

 «'onnected with this subject, are so satisfactory in their 

 results, both positive and negative, that a short reference 

 to them is essential to complete our notice of the question. 

 M. Pasteur first satisfied himself of the actual existence of 



* Edinburgh PhilosopLical Journal, Oct., 1859. 

 t Annalee des Sciences Naturelles. Ser. lY., torn. XII. (zool), p. 8G. 



