386 POISONS : THEIR EFFECTS AND DETECTION. [§ 450. 
and assayed according to the directions of the B.P. as follows :—Bella¬ 
donna root in No. 20 powder, 1000 grms. ; alcohol (90 per cent.) and 
distilled water, of each a sufficient quantity. Exhaust the belladonna 
root with a mixture of 7 volumes of the alcohol and 1 volume of 
distilled water by the repercolation process, until from every 3 grms. of 
the root 1 millilitre of strong percolate has been obtained. Determine 
the proportion of alkaloids in this strong percolate by the following 
process :—Introduce into a separator 10 millilitres of the strong percolate, 
50 millilitres of water, 2 millilitres of diluted sulphuric acid, and 10 
millilitres of chloroform. Shake vigorously, set aside until complete 
separation has taken place, draw off the lower layer, and wash it with 
two successive portions, each of 10 millilitres, of water acidified with 
diluted sulphuric acid. Add the washings to the upper layer left in the 
separator. Make the mixture distinctly alkaline with solution of 
ammonia, and extract the alkaloid by shaking with three successive por¬ 
tions, each of 10 millilitres, of chloroform. Mix the chloroformic solutions, 
shake with 10 millilitres of water, allow separation to take place, draw 
off the lower layer into a beaker, and set aside for the chloroform to 
evaporate. Heat the residue on a water-bath for thirty minutes, add 
10 millilitres of N/20 solution of sulphuric acid, warm gently until 
dissolved, and titrate back with N/20 solution of sodium hydroxide, 
tincture of cochineal being used as the indicator. Deduct the number of 
millilitres of alkaline solution required from 10 ; the remainder multi¬ 
plied by 0-01446 gives the number of grammes of the alkaloids contained 
in 10 millilitres of the strong percolate. To the remainder of the strong 
percolate add sufficient of the alcoholic menstruum to produce a liquid 
extract of belladonna containing 0-75 grm. of the alkaloids of belladonna 
root in 100 millilitres. 
The other official preparations of the root are all for external use, viz. : 
Belladonna plaster, alkaloidal content 0-25 per cent. 
Belladonna liniment, containing camphor, alcohol, and liquid extract 
of belladonna. Alkaloidal content 0-375 per cent. 
Belladonna suppositories, made with cocoanut oil and liquid extract, 
and each weighing about 1 grm. Alkaloidal content approximately 
1 mgrm. in each suppository. 
Belladonna ointment, made with wool fat, benzoated lard, and liquid 
extract of belladonna. Alkaloidal content 0-6 per cent. 
(c) The Alkaloid.—Atropine Discs (lamellae atropince). —These are 
discs of gelatine, each weighing about fo grain, and containing for 
ophthalmic use 1-3 mgrm. (50V0 grain) of atropine sulphate. Similar 
discs are made for hypodermic use, but stronger, each containing 
grain. Solution of Atropine Sulphate. —Strength 1 per cent. Atropine 
Ointment. —Strength 2 per cent, of atropine. 
(d) Stramonium. —An extract of the seeds is official in Britain ; 
