42 On t)>: WichilVs TJmw^-, ci'c. ■ 



neighbourhood of thn city of New York, On this projeA 

 Dr. Mitchill was confuhcd. The man's intention was to 

 have petitioned for the privilege of h9.ving the dirt and 

 fcrapings of the ftreets as a reward for keeping them clean. 

 And from this mafs of nuifance, whofe vapour in the hot 

 feafcn gaiw the people their jelloiu fevers y he intended to ex- 

 traft the nitre. After much confideration of the projcA it 

 was finally given up, as about that time the Secretar)^ of State 

 reported to Congrefs tliat a confiderable quantity of that 

 TTaterial had been brought to Philadelphia from fome pact of 

 the weftcrn country, and that any quantity required for the 

 public defence might be procured from that quarter. 



From a comparifon of all the fa6ls which had thus come 

 to his knowledge. Dr. Mitchill found that fome of the prin- 

 ciples in \\ hich he had been inftruftcd, were not fo well 

 rftabliflicd as they ought to have l>ecn. A number of the 

 darling prejudices of his education were in danger of being 

 overturned. And he, for fome time, experienced no fnialj 

 degree of affli&ion at the thought of rejecting much of what 

 he had learned from books and leclnrcs, concernincr acids 

 and alkali?, as groundlefs and untenable doftrine. 



The fluids, whether liquid or aeriform, which prA-ajh 

 could coerce, and which, as they cmane from putrefying 

 bodies, combine with that alkaline fait into nitre, thus ap- 

 peared- to be the very noxious miafmata which vitiated the 

 atmofphere and rendered it ficklv and vmwholefome, when 

 there was too little alkali or none at all to at1ra6l them. 

 Thefe feemed to be evidence enough to convince him, and 

 any body elfe who would examine thc'fafts as he had done, 

 that fome combination of azote with oxygen was the fimpleft 

 and moft common form of poifon. 



At the fame time he was perfe<?tlv aware that v\hat he 

 thus called a poifon, was what mankind knew under the 

 name of the nitrous acid ; that 7iitre zcas called a great anti- 

 feptic; that the arid was clafil-d among the viineral acids, and 

 was reckoned a. gre(it antifepiic too; with a multitude of fay* 



insfS 



