NITROGEN. 9^ 



explosive, and it then produces the peculiar blue flames 

 which occur by spontaneous combustion as the gas es- 

 capes in bubbles from wet marshes. It is also the gas 

 which is found in deep crevices in the rocks far beneath the 

 surface in localities where petroleum exists, and which is 

 sought for by boring, and used for illuminating purposes 

 and for fuel for engine furnaces. 



Another compound of carbon with hydrogen is the com- 

 mon gas distilled from coal and used for illuminating pur- 

 poses. Its more brilliant light is due to the fact that it 

 contains twice as much carbon as the previously mentioned 

 gas. 



It also forms a part of all oils, fats, resins and wax ; be- 

 ing combined in these with carbon and oxygen in varying 

 proportions. It is a constituent of petroleum and all its 

 products, including the beautiful aniline dyes which are 

 made from it. It also enters into the composition of woody 

 fiber, and the starch, gum, sugar and alcohols, which are 

 products of it ; both naturally and artificially. It is thus 

 a most important element, and offers to the studious farmer 

 a subject for study of great interest. 



A number of very pleasing experiments may be made 

 Avith it, such as its production by the decomposition of water ; 

 the formation of water by its combustion and union with 

 oxygen ; its combustion and oxidation by means of a porous 

 substance, as spongy platinum and the formation of its 

 compounds. 



NITROGEN. 



This gas was discovered in 1772 by a chemist named 

 Rutherford. It is diffused extensively in nature forming 

 four-fifths of the atmosphere ; entering largely into the com- 

 position of vegetable and animal substance, and being a 

 most indispensable part of the food of plants and animals. 

 About one-sixth of all animal tissue consists of this gas. 

 It forms a part of many of our powerful medicines, as qui- 

 nine and morphine, and of the most dangerous poisons as 

 strychnine and prussic acid. It is not found in any of the 



