Bept.] NATURAL SCIENCES OF PHILADELPHIA. 5 



consists of a white or light gray deposit of a shred-like and flocculent 

 appearance, Examined under the microscope this is seen to be princi- 

 pally composed of amorphous matter with which, however, starch granules 

 and cells of vegetable origin, together with masses of woody tissue and 

 fragments of silica are mingled. No animal structures are to be detected 

 on the most minute examination. 



Vao subjected to the action of heat acts in a manner not distinguish- 

 able from that of corroval, giving off a vapor with similar odor and other 

 properties to that derived from the latter substance. 



Woorara, of which corroval and vao may with propriety be considered 

 as constituting species, has been analyzed by Roulin and Boussingault,* 

 Pelletier and Petrozf and Heintz.} 



Roulin and Bmissingault experimented with woorara which had been 

 obtained from the Rio Negro. It was a solid extract of a black color, 

 but brown when reduced to powder, of a. resinous appearance, and ex- 

 ceedingly bitter taste. It burned with difficulty, and gave off no odor of 

 organic nitrogenous substances. It was soluble in water, alcohol and in 

 sulphuric ether, though not to any considerable extent. The aqueous 

 infusion was of slight acid reaction ; no strychnine was discovered by 

 these chemists in woorara. 



We may here state that two specimens of ordinary woorara, which we 

 owe to the kindness of Major LeConte, of Philadelphia, and Prof. J. (J. 

 Dalton, of New York, agree in all essential particulars with that above 

 described. 



By the following process, Roulin and Boussingault obtained from 

 woorara a new principle of an alkaloidal character, which they called 

 curarin. 



The woorara was reduced to fine powder and treated repeatedly with 

 boiling alcohol. The extract thus obtained was evaporated, and the 

 solid residue treated with water, which dissolved the active principle, 

 leaving nothing but a little resinous matter. The aqueous solution was 

 then decolorized by animal charcoal, and treated with infusion of galls. 

 A beautiful whitish-yellow, flaky precipitate was then thrown down, having 

 an exceedingly bitter taste. The supernatant liquid was almost entirely 

 deprived of its bitterness; the precipitate thus obtained was well washed, 

 heated to ebullition in water, and dissolved by the addition of oxalic acid. 

 The acid liquor was then supersaturated by magnesia and filtered. It 

 was again evaporated to dryness, and the residue dissolved in alcohol. 

 This solution was concentrated and spontaneously evaporated to a syrupy 

 consistence. It was subsequently further concentrated by evaporation in 

 vacuo. 



The analysis of Pelletier and Petroz yielded a similar product. These 

 chemists extracted the woorara with alcohol, and treated the tincture thus 

 obtained with ether, in order to remove the fatty and resinous substances 

 present. The alcoholic extract was then evaporated, dissolved in water, 

 and foreign matters precipitated from the solution by the acetate of lead, 

 the excess of lead being removed by sulphuretted hydrogen. The solution 

 was then decolorized by animal charcoal, filtered and evaporated ; sul- 



* Examen Chimique du Curare, Poison des Indiens de I'Orinoque, Annates de Chimie 

 et de Physique, Tome xxxix, 1828, p. 24. 



t Examen Chimique de Curare, Annates de Cliimic et de Physique, Tome xl. 1829. 

 p. 213. 



I Reisen in British Guiana, Von Richard Schomburgk, Bandi, S. 452, (noteX 



I860.] 



