ON GUM AND SUGAR TREES 



right combination to produce organic substances. 

 And, although this work is only at its beginning, a 

 good measure of success has been attained. 



In particular, the chemists of Germany and 

 England have recently succeeded in combining 

 carbon and hydrogen in the proportion of 8 atoms 

 of the former to 7 of the latter and thus have 

 produced an artificial rubber that is not merely 

 an imitation rubber but is as truly pure rubber as 

 if it had been produced in the cellular system of 

 a plant. 



Indeed, the artificial product may be said to be 

 somewhat more pure than the natural, inasmuch 

 as the latter is more or less contaminated by ex- 

 traneous products. 



Reference has elsewhere been made to the 

 familiar feat of the chemist through which the 

 famous dyestuffs, indigo and madder, have been 

 manufactured in the laboratory, and manufac- 

 tured so cheaply as to compete successfully with 

 the natural product of the indigo and madder 

 plants. What was a large plant industry only a 

 few years ago has thus ceased to have importance. 

 The indigo plant is still cultivated in the east, but 

 the entire industry has been changed by the dis- 

 coveries of the chemist. 



Only a few years ago a plant known as the tar 

 weed (Madia), to which we have had occasion to 



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