316 poisons : their effects and detection. [§§ 374 , 375 . 
§ 374. Effects. —Narcotine in itself has toxic action only in rather 
large doses ; from 1 to 2 grms. have been given to man, and slight 
hypnotic effects have followed. It is poisonous in very large doses ; 
an ordinary-sized cat is killed by 3 grms. The symptoms are mainly 
convulsions. 
§ 375. Codeine (Codomethylene), C 17 H 17 OCH 3 (OH)NO-f H 2 0, is the 
monomethyl ester of morphine ; it is an alkaloid contained in opium 
in small quantity only. Mulder, indeed, quotes -66 to *77 per cent, as 
present in Smyrna opium, but Merck and Schindler give -25 per cent. 
Schindler found in Constantinople, -5 per cent; and Merck, in Bengal, 
•5 per cent. also. 
Codeine crystallises out of dry ether in small, colourless, anhydrous 
crystals ; but crystallised slowly from an aqueous solution, the crystals 
are either in well-defined octahedra, or in prisms, containing one atom of 
water, and melting in boiling water to an oily fluid. The anhydrous 
crystals have a melting-point of 155°, and solidify again on cooling. Its 
watery solution is alkaline to litmus-paper. 
It requires 80 parts of cold, 17 of boiling water, 76 of carbon tetra¬ 
chloride, 10 parts of benzole, and 7 parts of amyl alcohol respectively, 
for solution. Alcohol, benzene, ether, carbon disulphide, and chloroform 
freely dissolve it, but in petroleum ether it is almost insoluble. Further, 
it is also soluble in aqueous ammonia and in dilute acids, but insoluble 
in excess of caustic potash or soda, and may thus be thrown out of an 
aqueous solution. A solution of codeine turns the plane of polarisation 
to the left, [a]r = 118*2°. 
Concentrated sulphuric acid dissolves codeine without colour, but after 
eight days the solution becomes blue ; this reaction is quicker if the acid 
contains a trace of nitric acid. If the sulphuric acid solution be warmed 
to 150°, and a drop of nitric acid be added after cooling, a blood-red 
colour is produced. Frohde’s reagent produces a dirty green colour, 
soon becoming Prussian blue, and terminating after twenty-four hours 
in a pale yellow. 
Cyanogen gas, led into an alcoholic solution of codeine, gives first a 
yellow and then a brown colour ; lastly, a crystalline precipitate falls. 
On warming with a little sulphuric acid and ferric chloride, a blue colour 
is produced. This blue colour is apparently common to all ethers of the 
codeine class. 
Of the group reagents, the following precipitate solutions of codeine : 
—Mercuric potassium iodide, mercuric chloride, mercuric bromide, picric 
acid, and tannin solutions. The following do not precipitate :—Mercuric 
cyanide and potassium ferrocyanide solutions. Potassium dichromate 
gives no immediate precipitate, but crystals form on long standing. It 
does not give the reaction with iodic acid like morphine ; it is dis¬ 
tinguished from narceine by dropping a small particle of iodine into the 
