Chemistry. 185 



39. Action of Nitric Acid on Charcoal. Professor Silliman having an- 

 nounced the formation of hydrocyanic acid, by the action of nitric acid 

 in charcoal, M. Frisiani was led to the same result in the following 

 manner : in treating with nitric acid the residue of the calcination of sul- 

 phate of barytes with charcoal, he smelt bitter almonds. This made him 

 suppose that the prussic acid was formed. He repeated the experiment in 

 a glass bottle, and heating the liquor with sulphate of iron, he obtained 

 prussian blue. The boiled nitrates and that of barytes, decomposed by 

 charcoal, do not produce the same effect. Giorn. de Fis. &c. 182*, 

 p. 240. 



40. Temperature of different Animals. M. Despretz has obtained the 

 following results on the temperature of different animals, that of the 

 air being 59° Fahrenheit. 



Two Carps, temperature of water 51\4 53.* Fahr. 



An adult Guinea Pig 96. 4 



3 male children, aged between 1 and 2 .years, 95. 2 



4 young persons aged 18 98. 6 

 9 men aged 30 98.83 

 4 men aged 68 98.83 

 A dog 3 months old 103.06 

 Three pigeons 109.37 



Respecting the cause of animal heat, M. Despretz has drawn the fol- 

 lowing conclusions : 



1. That respiration is the principal cause of animal heat, producing 

 seven-tenths of it in very young animals, and often as much as nineteen- 

 twentieths of the whole effect ; the remaining heat being produced by as- 

 similation, the motion of the blood, and the friction of the different parts. 



2. That besides the oxygen employed in the ^formation of the carbonic 

 acid, another portion of gas, sometimes very considerable in relation to 

 the first, disappears also ; more oxygen disappearing in general in young 

 than in adult animals. 



3. That there is an exhalation of azote in the respiration of mammife- 

 rous, carnivorous and granivorous animals, and in the respiration of birds ; 

 and that the quantity of azote exhaled is greater in granivorous than in 

 carnivorous animals. Bull, des Sc. Nat. &c. Avril 1825, p. 244 — 246. 



41. Analysis of the Piney Tallow from Malabar. This curious sub- 

 stance is obtained by boiling the fruit of the Valeria Indica or Piney, a 

 tree common on the coast of Malabar. The tallow rises to the surface in a 

 melting state, and forms a solid cake on cooling. In this state it is general- 

 ly white, sometimes yellow, greasy to the touch, with some degree of 

 waxiness, almost tasteless, and has rather an agreeable odour, somewhat re- 

 sembling common cerate. It melts at a temperature of 97 i 3 Fahrenheit. It 

 is so tenacious and solid, that 9 lbs. of it cast in a rounded form, could not 

 be cut asunder by the force of two strong men with a fine iron wire, and 

 it was very difficult to effect a division of it, even with a saw. Its specific 

 gravity at 974° is .8965 and at 60' .9260. According to the analysis of Mr 



