486 



SCIENCE. 



[N. S. Vol. XXIV. No. 616. 



no perceptible disturbance of the general 

 condition could be observed, it could be 

 assumed that saccharine had no deleterious 

 influence whatsoever upon the general 

 health. 



With the introduction of this artificial 

 sweetener, a new industrial field was 

 opened up, and the significance of this dis- 

 covery can be easily imagined when you 

 consider that four pounds of this material 

 are equivalent in sweetening power to one 

 ton of cane or beet sugar. It was soon 

 manufactured on such a large scale that 

 it seriously threatened the beet sugar 

 industry of the continent, and as the 

 latter was of much more economic im- 

 portance than the production of sac- 

 charine, laws were enacted which pro- 

 hibited the industrial use of the sweetener 

 as a substitute for sugar, permitting its 

 employment solely for medical purposes, 

 the German government even going so far 

 as to make a sort of state monopoly of the 

 manufacture of this material. 



Still another industry has undergone 

 vast changes through Perkin's discoveries 

 and since the beginning of the -coal tar 

 epoch — the manufacture of artificial per- 

 fumes. Nitrobenzol, under the name of 

 mirbaneoil, was in the market as artificial 

 oil of bitter almonds even before Perkin's 

 mauve. It was used to some extent for 

 scenting soaps. To-day a great variety of 

 synthetic perfumes are manufactured. 

 The odor of musk is successfully imitated 

 by a nitrated hydrocarbon derived from 

 coal tar; the odor of violets, of roses, of 

 jasmine, of heliotrope, is reproduced arti- 

 ficially by synthetic substances, and the 

 favorite American flavor, the oil of winter- 

 green, is manufactured from coal tar. And 

 in this art also the hand of the master 

 is seen in what is called the Perkin Reac- 

 tion, through which he first succeeded in 

 preparing from coal tar, coumarin and 

 cinnamic acid. 



The singular correlation of all these coal 

 tar products appears from the fact that 

 the odoriferous principle of jasmine is de- 

 rived from the same mother substance 

 which furnishes synthetic indigo, namely, 

 anthranilic acid. 



Between the products giving the sweet 

 odors of flowers and the death dealing ex- 

 plosives there would seem to be a broad 

 chasm, but not for the synthetic coal tar 

 chemist. In fact the same nitrobenzol 

 which was the first artificial perfume is 

 used to-day with nitroglycerin as a safety 

 explosive. The latter has the disadvantage 

 of congealing when exposed to the cold and 

 then becoming highly dangerous; the ad- 

 mixture of nitrobenzol keeps it liquid at 

 very much lower temperatures. Trinitro- 

 benzol and its homologues, especially trini- 

 trocarbolic acid, or picric acid, are to-day 

 employed as safety explosives by the miner 

 and in proper mixtures as smokeless 

 powder by the armies of the civilized 

 world. 



While coal tar preparations thus destroy 

 life, so they likewise sustain life, for by 

 the use of salicylic and benzoic acids, both 

 products of nature but now derived chiefly 

 from this source, it becomes possible to 

 preserve the canned foods so indispensable 

 to the soldier, sailor and explorer. 



In conclusion, mention must be made 

 of the use of coal tar colors and prepara- 

 tions in the reproductive arts, in v/hich 

 they play a most important part. Inks 

 for printing and writing are made with 

 coal tar colors and in photography coal 

 tar preparations are now used almost ex- 

 clusively for the development of the latent 

 pictures on films, plates and paper. By 

 the addition of certain coal tar colors to 

 the photographic emulsion the latter be- 

 comes extremely sensitive to light and can 

 then be used for instantaneous exposures, 

 as in snapshots, and thus kodak fiends are 

 the direct offshoots of the coal-tar industry. 



