320 poisons: their effects and detection. [§§ 380 , 381 . 
solution of iodine, added to an alcoholic solution of papaverine, separates in a little 
time crystals of the composition Cg'oH^NO^. From the mother-liquor, by con¬ 
centration, can be obtained needles of another iodine combination, C 20 H 21 NO 4 I 6 ; the 
latter heated above 100° parts with free iodine. Those compounds with iodine are 
decomposed by ammonia and potash, papaverine separating. The decomposition 
may be watched under the microscope. Nitric acid precipitates from a solution of 
the sulphate a white nitrate soluble in excess ; the precipitate does not appear at once, 
but forms in the course of an hour ; it is at first amorphous, but subsequently crystal¬ 
line ; this, with its physical properties, is a great assistance to identification. Papa¬ 
verine is a derivative of isoquinoline ; it contains four methoxyl groups. Goldschmiedt 
ascribes to it the following formula :— 
N 
0CH 3 
§ 380. Effects. —Claude Bernard ranked papaverine with the convulsants ; prob¬ 
ably the papaverine he had was impure. In any case, subsequent observations 
have shown that it is to be classed rather with the hypnotic principles of opium. 
Leidesdorf 1 administered it to the insane, and noted slowness of the pulse, muscular 
weakness, and drowsiness to follow. The doses were given subcutaneously (-42 grm. 
of the hydrochloride). Baxt , 2 experimenting with the frog, found that a milligramme 
caused deep sleep and slowing of the heart’s action. This action on the heart is 
witnessed also on the recently removed frog’s heart. Guinea-pigs and other small 
animals poisoned by strychnine or thebaine, and then given papaverine, did not 
seem bo be so soon affected with tetanus as when no such remedy was administered. 
In Bradbury’s experiments (Croonian Lectures, Lancet, July 1899) papaverine proved 
to be a powerful depressant. In rats 0-3 grm. per kilo, produced muscular weakness, 
slowing of the respiration and pulse, distinct narcosis, but no tetanus. 0-2 grm. 
per kilo, kills guinea-pigs by paralysis of the respiration in ten minutes. The fatal 
dose of papaverine for a man is unknown. The least quantity likely to cause dangerous 
symptoms would be 1 grm. (15-4 grains). 
§ 381. Thebaine, C 17 H 15 NO(OCH 3 ) 2 .—Opium seldom contains much more than 
1 per cent, of this alkaloid. It usually forms needles or short crystals. It is alkaline, 
and by rubbing becomes negatively electric. It is almost insoluble in water, aqueous 
ammonia, and solutions of the alkalies. It requires 10 parts of cold alcohol for 
solution, and dissolves readily in hot. Ether, hot or cold, is also a good solvent. 100 
parts of benzene are required for 5-27 parts of thebaine, and 100 of amyl alcohol for 
1-67 parts. Chloroform dissolves thebaine with difficulty out of both acid and alkaline 
solutions ; petroleum ether extracts it from neither. Thebaine melts in a tube at 
193°, sublimes at 135°. The sublimate is in minute crystals, similar to theine ; at 
higher temperatures (160° to 200°) needles, cubes, and prisms are obtained. The 
residue is fawn-coloured. Frohde’s reagent (as well as concentrated sulphuric acid) 
dissolves it, with the production of a blood-red colour, passing gradually into yellow. 
The precipitate with picric acid is yellow and amorphous ; with tannic acid, yellow; 
with gold chloride, red-yellow ; and with platinic chloride, citron-yellow, gradually 
becoming crystalline. A concentrated alcoholic solution of thebaine, just neutralised 
with HC1, deposits well-formed rhombic crystals of the composition C 19 H 21 N0 3 HCl-f- 
CH 3 0 
CH °° w 
CH, 
/X 
OCEL 
1 Ztschr. d. Wien. Aerzte, pp. 43, 115, 1868. 
2 Arch. Anat. Phys., p. 70, 1869. 
