1876.] 



On the Deportment of Alkalized Urine, 



457 



IV. Note on the Deportment of Alkalized Urine/'' By 

 Professor Tyndall^ F.R.S. Received December 18_, 1876. 



The communication " On the Influence of Liquor Potassae and an 

 Elevated Temperature on the Origm and Growth of Microphytes," which, 

 at Dr. E,oberts's request, I have had the pleasure of presenting to the 

 E-ojal Society, causes me to say earher than I should otherwise have done 

 that the subject w^hich has occupied Dr. Eoberts's attention has also occu- 

 pied mine, and that my results are identical with his. 



In some of the experiments the procedure described by Dr. Eoberts 

 was accurately pursued, save in one particular which has reference to 

 temperature. Small tubes with their ends finely drawn out were charged 

 with a definite amount of caustic potash, and subjected for a quarter of 

 an hour to a temperature of 220° Pahr. They were then introduced 

 into flasks containing measured quantities of urine. The urine being 

 boiled for five minutes, the flasks w^ere hermetically sealed during ebul- 

 lition. They were subsequently permitted to remain in a warm place 

 sufficiently long to prove that the urine had been perfectly sterilized by 

 the boiling. The flasks were then rudely shaken, so as to break the 

 capillary ends of the potash-tubes and permit the Hquor potassae to 

 mingle with the acid liquid. The urine thus neutralized was subse- 

 quently exposed to a constant temperature of 122^ Pahr., which is pro- 

 nounced by Dr. Bastian to be specially potent as regards the generation 

 of organisms. 



I have not found this to be the case ; for ten flasks, prepared as 

 above described towards the end of last September, remained perfectly 

 sterile for more than two months. 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"^ Pahr. 

 they failed to show any signs of life. 



These results are quite in accordance with those obtained by Dr. 

 Eoberts. His potash-tubes, however, were exposed to a temperature of 

 280° Pahr., w^hile mine were subjected to a temperature of 220° only. 



With regard to the raising of the potash to a temperature higher than 

 that of boiling water, M. Pasteur is in advance both of Dr. Eoberts and 

 myself. In a communication to the Prench 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 hquid) to steriHzed 

 urine, no life is ever developed as a consequence of the alkalization*. 



* That alkaline liquids are more difficult to sterilize thau acid ones was announced 

 by Pasteur more than fourteen years ago. See * Annales de Ohimie/ 1862, yol. Ixir. 

 p. 62. 



