SYNTHETIC CHEMISTRY. 43 



As an example of this class of syntheses, the alcohols may be cited. 

 Ordinary or wine alcohol is one of a large class of bodies which have 

 similar features, and to which the same general name has been given ; 

 they constitute a series : thus, we have methylic alcohol, vinic alcohol, 

 tetrylic alcohol, and so on. Now, in most of these we can substitute 

 certain metals for hydrogen ; for instance, metallic zinc can be thus 

 inserted, and hydrogen removed, yielding zinc-ethyl, and, with the ad- 

 dition of oxygen, zinc-alcohol, and we get a colorless, fragrant liquid, 

 in which, singularly enough, the zinc has so far lost its usual charac- 

 teristics as to be both invisible and volatile. By carrying on the steps 

 of this process still further, several metals may be introduced leading 

 to the production of bodies of great resultant complexity, but which, 

 through all their metamorphoses, are yet true members of the alcohol 

 family. 



In this sense the artificial processes may be said to surpass the 

 natural ones ; for man is able to add many individuals to a series of 

 which Nature presents us with only scattered terms ; and, in addition, 

 in this particular group, he is able to form some of the natural mem- 

 bers, such as wine alcohol and glycerine, by a direct process of con- 

 struction, starting with the free elements, carbon, hydrogen, and oxy- 

 gen. The method is briefly as follows : Carbon, in the form of black- 

 lead, and therefore strictly a mineral substance, is heated intensely 

 between the poles of a galvanic battery ; when it is brilliantly incan- 

 descent, hydrogen gas is made to pass over its surface, in a suitable 

 apparatus, the sides of which are kept comparatively cool, and the 

 result is the formation of an invisible but extremely irritating gas, 

 known as acetylene. Now, if acetylene is brought into a solution of 

 copper, it combines with it, forming a dark-red explosive compound, 

 and, if we act upon this body by hydrogen, the copper will be expelled, 

 and olefiant gas, a sweetish ethereal substance, is obtained; and, 

 finally, by distilling this last with sulphuric acid, alcohol is one of the 

 products. Thus, in the several steps leading to this result, only min- 

 ^eral matter and ordinary chemical forces have been employed. 



It must not be inferred, from the above meagre examples, that the 

 number of syntheses is equally limited. Already there have been 

 formed several natural vegetable acids, many of the alcohol family, 

 some of the sugars, a whole host of ureas, a multitude of bodies analo- 

 gous to the vegetable alkaloids, as well as many of the natural flavor- 

 ing and coloring agents ; these last, indeed, on an extended commer- 

 cial scale. 



So far as the evidence of experience goes, there seems no limit to the 

 possible production of organic bodies which possess a definite chemical 

 structure, at least of those which have the power of crystallizing, for 

 the number, even now beyond the powers of an ordinary memory, is 

 constantly increasing in an accelerating ratio, and already, as has been 

 referred to, in some instances exceeds the range of Nature herself. 



