336 APPENDIX. 



prepared as above described towards the end of last 

 September, remained for more than two months perfectly- 

 sterile. I have no doubt that they would have remained 

 so indefinitely. 



Three retorts, moreover, similar to those employed by 

 Dr. Bastian, and provided with potash-tubes, had fresh 

 urine boiled in them on the 29th of September, the retorts 

 being sealed during ebullition. Several days subsequently, 

 the potash-tubes were broken and the urine neutralized. 

 Subjected for more than two months to a temperature of 

 122° Fahr. they failed to show any signs of life. 



These resiilts are quite in accordance with those ob- 

 tained by Dr. Roberts. His potash-tubes, however, were 

 exposed to a temperature of 280° Fahr., while mine were 

 subjected to a temperature of 220° only. 



With regard to the raising of the potash to a tempera- 

 ture higher than that of boiling water, M. Pasteur is in 

 advance both of Dr. Roberts and myself. lu a communi- 

 cation to the French Academy, on the 17th of last July, 

 M. Pasteur showed that when due care is taken to add 

 nothing but potash (heated to redness if solid, or to 110° 

 C. if liquid) to sterilized urine, no life is ever developed 

 as a consequence of the alkahzation.' 



M. Pasteur has quite recently favoured me with 

 sketches of the simple but effectual apparatus by means 

 of which he has tested the conclusions of Dr. Bastian. 

 Since his return from his vacation at Arbois, he has care- 

 fully gone over this ground with results, he reports to me, 

 not favourable to Dr. Bastian's views. 



I may add that I have by no rueans confined myself tii 

 the thirteen samples of urine here referred to. The ex- 

 pei'iments have already extended to one hundred and five 

 instances, not one of which shows the least countenance 

 to the doctrine of spontaneous generation. 



' That alkaline liquids are more difiicult to sterilize than acid 

 ones was armoiinced by Pasteur more than fourteen j'ears ago. See 

 'Annales de Chimie,' 18G2, vol. Ixiv. p. 62. 



