252 POISONS : THEIR EFFECTS AND DETECTION. [§ 309 . 
mixture diluted with water, so that 10 parts of the solution contain 1 of 
the dry salt. The precipitates of the alkaloids are as follows :— 
Aniline 
Bright yellow, flocculent. 
Morphine . 
99 99 
Narcotine 
Brownish-yellow, „ 
Quinine . 
Whitish-yellow, „ 
Cinchonine 
99 99 
Codeine . 
Brownish-yellow, voluminous. 
Strychnine 
White-yellow, „ 
Brucine . 
Bright yellow, flocculent. 
Veratrine. 
Jervine . 
77 7 7 
Aconitine 
99 • » 
Emetine . ... 
77 77 
99 99 
Theine 
„ voluminous. 
Theobromine . 
99 99 
Solanine . 
Citron-yellow, pulverulent. 
Atropine . 
Bright yellow, flocculent. 
Hyoscyamine . 
99 99 
Colchicine 
Orange-yellow, „ 
Delphinine 
Grey-yellow, voluminous. 
Berberine 
Dirty yellow, flocculent. 
Coniine . 
Bright yellow, voluminous. 
Nicotine . 
99 99 
Piperine . 
• 
Brownish-yellow, flocculent. 
2. Silico-Tungstic Acid as 
a Reagent for Alkaloids.— Sodium tung- 
state is boiled with freshly precipitated gelatinous silica. To the solution 
is added mercurous nitrate, which precipitates the yellow mercurous 
silico-tungstate. This is filtered, well washed, and decomposed by an 
equivalent quantity of hydrochloric acid ; silico-tungstic acid then goes 
into solution, and mercurous chloride (calomel) remains behind. The 
clear filtrate is evaporated to drive off the excess of hydrochloric acid, 
and furnishes, on spontaneous evaporation, large, shining, colourless 
octahedra of silico-tungstic acid, which effloresce in the air, melt at 36°, 
and are easily soluble in water or alcohol. 
This agent produces no insoluble precipitate with any metallic salt. 
Caesium and rubidium salts, even in dilute solutions, are precipitated by 
it; neutral solutions of ammonium chloride give with it a white precipi¬ 
tate, soluble with difficulty in large quantities of water. It precipitates 
solutions of the salts of quinine, cinchonine, morphine, atropine, etc. ; 
if in extremely dilute solution, an opalescence only is produced : for in¬ 
stance, it has been observed that cinchonine hydrochlorate in , 
quinine hydrochloride m ^.Wo, morphine hydrochloride in 
dilution, all gave a distinct opalescence .—Archiv der Pharm Dr Richard 
Godeffroy. 
According to Gabriel Bertrand ( Compt . Rend., cxxviii. 742), the salts 
possess the general formula 12Wo0 3 Si0 3 Alk-f nH 2 0, the morphine salt 
has the formula of 12Wo0 8 Si0 8 ,2H 8 04C 47 H 19 N0 3 + 9H,0; dried at 
