Note 146 — XXII. (continued 2)

Cocain is precipitated in colourless inodorous prismatic crystals. It is with difficulty soluble in water, but melts readily in alcohol, and with still more facility in ether. When dissolved in alcohol, the solution becomes a strong alkaline reagent, and has a peculiar slightly bitter taste. When brought in contact with the nerves of the tongue, it possesses the singular property of deadening sensation after a few seconds have elapsed, in the part to which it has been applied, which for a time becomes almost void of feeling. It fuses at a temperature of 208°.4 Fahr., and in cooling resumes its former prismatic crystalline form. When heated beyond this temperature, it changes to a reddish hue, and volatilizes with a strong ammoniacal odour. Only a small portion seems to get liberated by the destructive process. When heated on a platinum disc, it burns away with a bright flame, leaving no residuum. Cocain completely neutralizes acids, although most of the resulting salts seem to crystallize with difficulty, and to remain for a considerable time in an amorphous state. The resultant chloride seemed the most readily formed as well as delicately shaped of the crystals. Cocain exposed in chlorine is followed by such a development of heat that the former is fused. (Compare "Cocain, an Organic Base in the Coca," letter of Professor F. Wöhler to W. Haidinger, acting Fellow of the Imperial Academy of Sciences, presented at the meeting of the Class of Mathematics and Physical Science, 8th March, 1860. See also "On a New Organic Base in the Coca-leaves," Inaugural dissertation on attaining the degree of Doctor of Philosophy at Göttingen, by Albert Niemann of Goslar. Printed at the Göttingen Press, 1860.)