1892.] NEW YORK ACADEMY OF SCIENCES. 109 



Paris, published a more complete treatise in the year 1675. These 

 were the first glimmers of the dawn soon to break in chemical 

 history, and especially in the domain of organic chemistry. Up to 

 this time the work had been fragmentary and erratic. No particular 

 line of research had been followed by any experimenters and no 

 leading or intellio-ent course laid down for future work. 



The reason for this dormant state of the organic side of chemistry 

 is probably found in the development of metallui'gy. The alche- 

 mists, who lived but for one oljjeet, the conversion o5 the base metals 

 into gold, caused the drift of all experimental work in that direc- 

 tion ; in other words, they encouraged the inorganic rather than 

 the organic development of experimental chemistry. Nevertheless, 

 certain truly organic substances were discovered and their proper- 

 ties prett}^ well known. But the healing art was almost exclusively 

 confined to metallic compounds during the early part of the eighteenth 

 century, and it took some time before organic medicines were used 

 at all. Gradually organic bodies, especially plants, were used and 

 their active principles separated from them. This led to the dis- 

 covery of such bodies as succinic acid from amber, benzoic acid from 

 gum benzoin, pyroligneous acid, the crude acetic acid, from %\ood, 

 and sugar of milk from cow's milk. 



Nicholas Lemery classified all substances under three heads, mine- 

 ral, vegetable, and animal, according to their origin ; and this was 

 the best he could do. 



Such was about the condition of affairs in chemistry until near 

 the close of the last century (IT 74), when the Swedish apothecary, 

 Karl Scheele, made the first important advances in the investiga- 

 tion of organic substances. Befoi'e this time all the organic chemi- 

 cal investigations had been made solely for the purpose of obtaining 

 medicines and for the improvement of various technical processes, 

 such as dyeing and calico-printing. Scheele had the true spirit of 

 the scientific investigator, and made his experiments solely for the 

 purpose of obtaining a better knowledge of the character of the 

 materials that fell into his hands. He was the first to identify and 

 separate nearly all the common vegetable acids. He proved that 

 the acid of lemons (citric acid) was different from the acid of grapes 

 (tartaric acid), and that malic acid (from apples) is different from 

 either. He also separated and described the acid of wood-sorrel 

 (oxalic acid), and proved that it could be made from sugar by means 

 of nitric acid. Furthermore, he showed that another acid (lactic) 

 of a totally different character was obtained from sugar of milk by 

 the same ti'eatment with nitric acid. From nut-galls he obtained 

 gallic acid ; and from urine, uric acid ; and by treating fats with 

 oxide of lead and water he obtained the sweet principle of oils — as 

 he called it — glycerin, at the same time proving that by treatment 

 with nitric acid glycerin will give the same product as ordinary 

 cane-sugar, namely, oxalic acid. 



Chemistry owes to pharmacy a debt of gratitude for showing the 

 way to her modern fields of triumph, for the earliest and best 



