476 POISONS .* THEIR EFFECTS AND DETECTION. [§ 6oj. 
water. Picrotoxin, so prepared, is probably a mixture of two bodies— 
picrotoxinin, C 15 H 16 0 6 , and picrotin, C 15 H 18 0 7 , although some authors 
consider it to be a definite compound ; in any case, picrotoxin easily 
decomposes into these two bodies. 
The mixture crystallises out of water, and also out of alcohol, in 
colourless, flexible, four-sided prisms, often arborescent, and possessing 
a silky lustre. They are unalterable in the air, soluble in 150 parts of 
cold, and 25 parts of boiling water, in spirit, in ether, in amyl alcohol, 
chloroform, and the caustic alkalies. They are without smell, but have 
an extremely bitter taste. Caustic ammonia is also a solvent. 
The crystals are neutral in reaction. They melt at 199°-200° C. to 
a yellow mass; at higher temperatures giving off an acid vapour, with 
a caramel-like odour, and lastly carbonising. Picrotoxin in cold concen¬ 
trated sulphuric acid dissolves with the production of a beautiful gold- 
yellow to saffron-yellow colour, which becomes, on the addition of a trace 
of potassic bichromate, violet passing into brown. An alcoholic solution 
turns a ray of polarised light to the left [a] D =— 28T°. Heated with 
strong soda or soda lime, there is developed a strong smell like pepper¬ 
mint ; the odour is due to mesityl oxide. 
Picrotoxin when submitted to the action of hydriodic acid and 
phosphorus gives a ketone, C 14 H 16 0 3 . This ketone, treated with con¬ 
centrated alcoholic potassic hydroxide, produces in good yield a new 
compound, C 12 H 14 0 2 ; this compound crystallises in colourless needles, 
m.p. 81° ; it is volatile when steam-distilled, and has a celery odour. 
Heated with three times its weight of potassic hydrate, it yields acetone 
and 2 : 3 dimethyl-benzoic acid, the barium salt of which gives o-xylene 
when distilled with barium oxide. The ketone, C 14 H 16 0 3 , also yields 
acetone on fusion with potash from these and other reactions. Angelo 
regards picro-oxinine and picrotin as hydrobenzene derivatives. 
Acetone can be obtained from the picrotoxins quite easily, for N. baryta 
or N. potash solutions produce it even acting in the cold. Concentrated 
hydrochloric acid also splits off acetone, at the same time, according to 
Sielisch (Ber., 1912), accompanied by a substance C 12 H 24 0 2 , m.p. 84°, 
boiling-point 162° at 12 mm. pressure. 
Picrotic acid (C 15 H 18 0 4 ), according to Paul Horrman’s researches 
(j Ber., 1916), is a butyric acid substituted by a residue C 11 H 11 0 2 . It 
contains a carboxyl and a lactone group. 
Picrotoxinin (C 15 H 16 0 6 ) is best obtained by brominating picrotoxin 
in hot solution with a slight excess of bromine water, and removing the 
excess of bromine from the crystalline monobromopicrotoxinin, which is 
separated by means of zinc dust and acetic acid. It crystallises from 
hot water in colourless anhydrous crystals, and from cold water in 
rhombic plates. It melts at 200°-201° ; with H 2 S0 4 it gives an intense 
orange-red colour. Bromopicrotoxinin (C 15 H 15 Br0 6 ) melts at 259°-260°. 
