520 CONSIDERATION OF CARBON COMPOUNDS. 



They are also formed by the action of hydrocarbon chlorides (or 

 iodides) on salts. For instance : 



C 5 H U C1 + CH )0 : ^g)o + KC1 



Amyl Potassium Amyl Potassium 



chloride. formate. formate. chloride. 



Occurrence in nature. Many ethers are products of vegetable 

 life and occur in some essential oils ; wax contains the compound 

 ether melissyl palmitate, C 3(J H 61 .C 16 H 31 O.O, and spermaceti, a solid 

 substance found in the head of the whale, is cetyl palmitate, C^H^. 

 C 16 H 31 O.O. The most important group of esters are the fats and 

 fatty oils, which are distributed widely in the vegetable, but even 

 more so in the animal kingdom. 



General properties. The ethers and esters of the lower members 

 of the monatomic alcohols and fatty acids have generally a character- 

 istic and pleasant odor. Fruit essences consist mainly of such esters, 

 and what is generally known as the " bouquet " or " flavor " of wine 

 and other alcoholic liquors is due chiefly to ethers or compound ethers, 

 which are formed during (and after) the fermentation by the action 

 of the acids present upon the alcohol or the alcohols formed. The 

 improvement which such alcoholic liquids undergo " by age " is caused 

 by a continued chemical action between the substances named. 



All esters are neutral substances ; those formed by the lower alco- 

 hols and acids are generally volatile liquids, those of the higher 

 members are non-volatile solids. When esters are heated with alka- 

 lies, the acid combines with the latter, while the alcohol is liberated. 

 (The properties of the esters, termed fats, will be considered further 

 on.) 



One of the chief points of distinction between ethers and esters is 

 that ethers are not acted on by alkalies, while esters are decomposed, 

 an alcohol and a salt of the alkali metal being formed. 



Ethyl ether, Either, (C 2 H 5 ) 2 O = 73.52 (Ether, sulphuric ether, Ethyl 

 oxide). The name of the whole group of ethers is derived from this 

 (ethyl-) ether, in the same way that common (ethyl-) alcohol has 

 given its name to the group of alcohols. The name sulphuric ether 

 was given at a time when its true composition was yet unknown, and 

 for the reason that sulphuric acid was used in its manufacture. 



Ether is manufactured by heating to about 140 C. (284 F.) a 

 mixture of 1 part of alcohol and 1.8 parts of concentrated sulphuric 

 acid in a retort, which is so arranged that additional quantities of 

 alcohol may be allowed to flow into it, while the open end is connected 



