402 Changes in Albuminous Substances during Digestion. 



thick. As used in these experiments, it could maintain a current 

 nearly uniform for an hour. I commonly employ four pairs. 



Among writers on optics, it has been a desideratum to obtain 

 an artificial light of standard brilliancy. The preceding experi- 

 ments furnish an easy means of supplying that want, and give 

 us what might be termed a "unit-lamp." A surface of platinum 

 of standard dimensions, raised to a standard temperature by a 

 voltaic current, will always emit a constant light A strip of 

 that metal, one inch long and V^th of an inch wide, connected 

 with a lever by which its expansion might be measured, would 

 yield at 2000° a light suitable for most purposes. Moreover, it 

 would be very easy to form it an available photometer, by screen- 

 ing portions of the shining surface. An ingenious artist would 

 have very little difficulty, by taking advantage of the movements 

 of the lever, in making a self-acting apparatus, in which the 

 platinum should be maintained at a uniform temperature, not- 

 withstanding any change taking place in the voltaic current. 



University, New York, Feb. 27, 1847. 



Art. XXXYI. — On the Changes which the Albuminous Sub- 

 stances undergo in the Stomach, during the process of Diges- 

 tion; by Prof. Mulder, of Utrecht. (Translated from the 

 Dutch, by Dr. Aug. Volcker. ) 



I last year demonstrated,* that the fibrin of blood undergoes 

 no change in composition by solution in muriatic acid and precip- 

 itation by carbonate of ammonia. 



The results of my analysis, employing in the present instance 

 my last experiments on the amount of sulphur in these substan- 



ces, were as follows : 



Undissolved rthrin Dissolved and thrown down with 



undissolved Bonn. carbonate of ammonia. 



C, . . 527 



H, . . 6-9 



N, . . 15-4 



O, . . 23-5 



S, . . 1-2 



Ph, . . 0-3 



losnhorus has not hpp 



52-7 



69 



15-8 



23-5 



11 



tion ; but as vitellin loses phosphamid under the influence of ac 



tic 



t 



under 



ammonia 



* Scheik. Onderz., Deel iii, p. 470. 



t Von Baumhauer in Scheik. Onderz., Deel iii, p. 284- 



