188 ANNUAL REPORT SMITHSONIAN INSTITUTION, 19 40 



Many other illustrations might be cited to show how our older indus- 

 tries have been aided through products or techniques having their origin 

 in the organic chemical industry, but I shall mention only a few more. 



In the manufacture of perfumes, materials known as fixatives are 

 used, one function of which is to make the odor more lasting. Until 

 a few years ago, all fixatives were of animal origin, such as the musk 

 from a species of deer found in Tibet. The characteristic ingredient 

 of natural musk, if it could be had in a perfectly pure state, would 

 probably be worth its weight in gold several times over, but within 

 recent years synthetic musks have been developed, and at least one 

 of these new organic compounds is substantially identical with the 

 characteristic ingredient of natural musk. All sell at only a fraction 

 of the cost of the natural product. Moreover, the chemist has syn- 

 thesized certain floral odors which cannot well be recovered from 

 flowers. Perfumes having the true scent of lilac or lily-of-the-valley, 

 for example, were not to be had until the chemist synthesized these 

 elusive and delicate odors. Wholly new odors have also been syn- 

 thesized, but it should be understood that, for the most part, synthetic 

 perfume chemicals supplement rather than displace natural floral odors. 

 High quality perfumes are usually a skillful blend of the natural and 

 synthetic. 



The close relationship between organic chemicals and the explosives 

 industry is well illustrated by some of my own early experiences. One 

 of my first assignments after becoming affiliated with the du Pont 

 Company in 1907 related to the manufacture of ammonium nitrate, 

 used in certain types of dynamite. In particular we sought to find 

 the cause of repeated fires which occurred on evaporating the neutral- 

 ized ammonia liquors. Since this was before the days of synthetic 

 ammonia, the ammonia liquors came from byproduct coke ovens, and 

 were originally bought on the basis of their ammonia content. While 

 they were analyzed for various inorganic constituents, no attention 

 whatever was paid to the possibility of organic matter being present. 

 To make a long story short, I carefully investigated the ammonia 

 liquors and found relatively large amounts of volatile tars. When 

 the liquors were neutralized with nitric acid, some of these tars were 

 partially nitrated. When the neutralized liquors were concentrated 

 by evaporation, the deposit of unstable nitrated tarry matter along 

 the margin of the hot ammonium nitrate liquors often ignited spon- 

 taneously, and it was this that had caused some disastrous fires. I 

 thereupon worked out a quantitative method for the quick determina- 

 tion of the total tarry content of ammonia liquors, so that a specifica- 

 tion as to tarry content could be incorporated in connection with the 

 purchase of ammonia liquor. 



Another early assignment was a study of the nitration of toluene 

 in the production of a mixture of nitrated toluols used to lower the 



