OF ARTS AND SCIENCES. Ill 



paper by Schlumberger,* in which the action of a mixture of sulphuric 

 and boric acids on crude curcumin is studied, and a description given 

 of ihe product called by him rosocyanin, because it dissolved in 

 alcohol with a fine red color, and was turned blue by alkalies. lie 

 also describes a resinous product of the action of boric acid on curcumin 

 (pseudocurcumin). 



Two years later, in 18G8, Bolley, Suida, and Lange t examined the 

 turmeric oil, and published a new analysis of a purer curcumin (melt- 

 ing-point 120°) ; but it was not till 1870 that curcumin was obtained 

 essentially pure. In this year Daube,^ Ivanow-Gajewsky,§ and 

 Kachler || published independent papers on the subject, of which 

 Ivanow-Gajewsky's is entitled to the precedence, as the number of the 

 Beilin Berichte which contained Daube's original paper gave a notice 

 in the Correspondence of the reading of Gajewsky's paper before the 

 Russian Chemical Society a month earlier. In addition to an analysis 

 of the turmeric oil, he assigns, as the simplest possible, the formula 

 C^II^O to curcumin, which after crystallization from ether or benzin 

 melted at 172°. Daube, on the other hand, after extracting his curcumin 

 with benzol, and purifying it by conversion into the lead salt, obtained 

 the melting-point 165°, and the formula Cj^Hj^Oj. He also found 

 that it was decolorized by sodium amalgam and alcohol, and converted 

 into oxalic acid by dilute nitric acid. 



Kachler, who did not succeed in crystallizing his curcumin, although 

 both Ivanow-Gajewsky and Daube got crystals, obtained the same 

 formula as the former, that is, C^II^O, or some multiiile of it. He also 

 studied the action of sodium amalgam upon it, and that of hot zinc 

 dust, but with no very definite results in either case ; whereas by fusing 

 curcumin with potassic hydrate, he obtained protocatechuic acid. From 

 the turmeric oil he obtained essentially the same analytical results as 

 Ivanow-Gajewsky. 



In 1872 Ivanow-Gajewsky published a second paper 1[ on turmeric, 

 containing another method for extracting curcumin, which, however, 

 gave it a melting-point of 140°, and an analysis of the lead salt sup- 

 porting his formula C]6H,gO, (= (CJI^O)J. Moreover he confirmed 

 the results of Kachler with fusing potassic hydrate (protocatechuic 

 acid) and zinc dust, and states that the oil obtained with the latter is 

 identical with turmeric oil, of which a new analysis is given, and its 



* Bull. Soc. Cliim. ser. 2, v. p. 194. § Ibid., 1870, p. 624. 



t J. pr. Cliem., ciil. p. 474. || Ibid., 1870, p. 713. 



t Ber. d. ch. G., 1870, p. 609. 1[ Ber. d. ch. G., 1872, p. 1103. 



