1S2 Gerhard? s Organic Chemistry. 



spirit are the derivatives, a homologous body formene CH 4J which 



is marsh gas.* 



The product of the action of sulphuric acid upon alcohol 

 known by the name of ether, contains in an equivalent, = 2 vol- 

 umes of vapor, the elements of two equivalents of alcohol minus 

 one of water, 2(C , EL O) - H 2 0=C 4 H , O. It is found by 

 the accouplement of two molecules of alcohol, and like other 

 coupled bodies, by the influence of acids and chlorine, reassumes 

 the elements of water and yields products which are derived Iron 

 alcohol. It is evident that ether cannot exist in the ethers of 

 acids as Liebig supposes. The gaseous ether of wood-spirit 

 (methyiic gas, is Identical with alcohol ether in constitution. 



Glycerides. — The researches of Scheele and Chevreul have 

 shown that the vegetable and animal fats are decomposed by the 

 action of potash, lime, and other energetic bases, furnishing a 

 fatty acid and a sweet soluble substance, to Which the name of 

 glycerine is given. They were hence regarded as salts of glyce- 

 rine, until it was shown that this body could not exist in them, 

 when Berzelius proposed to consider them as compounds of the 

 acids with the oxyd of a compound radical, lipyle, which formed 

 glycerine by uniting with the elements of water. The inadequacy 

 of such theories has been already seen ; our author proposes to 

 regard them as compounds, which like the ethers are derived 

 from the elements of the acid and glycerine by the abstraction 

 of the elements of water. The glycerids of the monobasic acids 

 (the only ones as yet known) contain the elements of two equiv- 

 alents of the acid and one of glycerine minus three of water; 

 stearine is represented by 2C, 9 H, 8 2 -f-C 3 H 8 O, -3H 2 0*j 

 C 44 H 78 4 . The glycerids are decomposed by alkalies wtn 

 the assimilation of the elements of water ; concentrated sulp^ 

 ric acid acts in the same manner and forms a coupled acid vrw 

 the glycerine ; ammonia decomposes them and yields an am^ 6 

 of the acid : this has been observed in the case of margarine 

 which produces margaramide. , 



The principal glycerids known are those of the group ° 

 homologous acids mentioned on page 99 ; all of these acids, ^ 

 the exception of the formic, acetic, and metacetonie, are known 

 have corresponding glycerids. The phoeenine obtained by ^n 



j 



reul from porpoise-oil, is the glyceride of valerianic acid, wni 

 the researches of Dumas and Munro have shown to be identic 

 with the phocenic. 



The glycerids have hitherto been known only as the P^I lC ij s 

 of the vegetable and animal organism, but MM. Pelouze and t*e 

 have lately observed that on heating a mixture of butyric < 

 and glycerine, a neutral oily substance separates, which apF 



* See page 172. 



