Gerard’s Reaction on Theobromine.
A mixture of 0·05 g of theobromine, 3 ccm of water and ccm of soda wash is decomposed with 1 ccm of a silver nitrate solution 10 percent strong, heated to 60 C. and the solution so obtained cooled down. It then gelatinises very perceptibly. Caffeine does not give this reaction.
Cf. Pharmaceutical and Chemical Journal 1906, p. 476. Apoth.-Ztg. 1906, p. 432. Pharm. Ztg. 1906, p. 512. Chemical Leaflet 1906 II, p. 167 among others.
[182] Soxhlet’s so-called steam digester, as constructed by Esser of Munich.
[183] Ztschr. f. anal. Ch. 1882, Vol. 22, page 448.
[184] Giornale di Farmacia, di Chimica etc. 1898.
[185] Lectures for the Establishment of Rational Feeding of Animals (Weender, Lectures), vol. 1864, p. 48. Cf. also “Landwirtschaftl. Versuchsstationen”, vol. 4, page 497.
[186] Journal of Applied Chemistry 1896, p. 712 & 749.
[187] A new process for the determination of crude fibre in food stuffs. Z.U.N. u. G. 1898, p. 3.
[188] Ztschr. öff. Chemie 1899, vol. 2, p. 29.