974 



AN AMERICAN TEXT-BOOK OF PHYSIOLOGY. 



other time of its life. This iron is lost only very slowly, hence the very small quantity of 

 iron in the milk answers all necessities. The other salts of the milk are in the same pro- 

 portion to one another as are the salts in the newborn animal. 



Tables representing generally accepted analyses of the mineral constituents of the more 

 important fluids and cells of the body are subjoined. Only very pronounced differences 

 are to be taken into consideration in drawing conclusions, for analyses of animals of dif- 

 ferent species, or of the same species, or even of the same animal at different times, show 

 wide variations. The tables represent parts in 1000 of fresh substance : 



I. 



II. 



THE CHEMISTRY OP THE COMPOUNDS OF CARBON. 



DERIVATIVES OP METHANE. 



The complicated structure and the great variety of the compounds of car- 

 bon are due to the fact that carbon-atoms have a greater power for union 

 with one another than have the atoms of other elements. 



Saturated Hydrocarbons or Paraffins (formula, C n H 2n + 2 ). 



Methane, CH 4 , gas. Pentane, C 5 H 12 , liquid at 38. 



Ethane, C 2 H 6 , " Hexane, C 6 H M , " 71. 



Propane, C 3 H 8 , " Heptane, C 7 H 16 , " 98. 



Butane, C 4 H 10 , " etc. 



These are the constituents of petroleum and natural gas, and are formed by the action 

 of low heat on coal under pressure in the absence of oxygen, and are probably derived 

 a'om fossil animal fat, since it has been shown that the paraffins may be obtained in large 



1 Herter : Hoppe-Seyler's Physiologische Chemie, p. 192. 



1 Kroger : Quoted by Halliburton, Chemistry, Physiological and Pathological, p. 656. 



s Bidder and Schmidt: Quoted by Halliburton, Op. eit., p. 638. 



4 Hoppe-Seyler : Physiologische Chemie, p. 302. 



5 Bunge: Ibid., 3d ed., p. 265. 



6 Op. cit., p. 222 (Bunge finds Na 2 O exceeds K 2 O in the blood-corpuscles of cattle). 



7 Bunge: Zeitschrift fur physiologische Chemie, 1885, Bd. 9, p. 60. 



8 Bunge : Physioloyische Chemie, 3d ed., p. 100. 



