430 ORGANIC CHEMISTRY. 



food in large proportion. The use of bacon, with 

 peas, beans, and eggs, and many other popular mix- 

 tures of food, are accounted for on the principle above 

 stated. For the development of most of the views 

 presented in this chapter, the world is indebted to the 

 distinguished Liebig. 



ORGANIC ANALYSIS 



1067. ULTIMATE ANALYSIS. CARBON AND 



How are car- 

 bon and hy- HYDROGEN. The proportions of carbon 



'mined ? deter ~ an( ^ hydrogen in organic substances, is 

 ascertained from the quantity of carbonic 

 acid and water which they yield on combustion. The 

 combustion is effected in a glass tube, by means of 

 oxide of copper, and the products are collected by 

 means similar to those described in the process for an- 

 alyzing the air. 



1068. NITROGEN AND OXYGEN. Thepro- 



How are nitro- .... . , 



gen and oxy- portion of nitrogen m an organic substance 

 gendetermin- is usua n y determined by the quantity of 

 ammonia it will yield by combination 

 with hydrogen. This combination is effected by 

 heating the organic substance with hydrate of potassa 

 or soda. The quantity of the ammonia produced in 

 the process is estimated by the amount of acid it will 

 neutralize. From the weight of this compound, that 

 of the nitrogen it contains is readily calculated. The 

 amount of oxygen in an organic substance is ascer- 

 tained by subtracting the total weight of all the other 

 constituents. 



