ON THE TOXIC CONSTITUENTS IN THE BARK OF ROBINIA PSEUDACACIAL. 341 
Physical and Chemical Studies of the Toxin. 
I. SEPARATION OF TOXIN. 
Throwing away the outer rough parts, we skinned the bark and cut it 
into small pieces, then dried it in the shade. This material was treated with 
ether, cold and hot alcohol and water. 
(A) Ethereal extract, (about 5%):—The reddish brown ethereal extract 
has unpleasant odor and acid reaction. It scarcely dissolves in water and has 
not toxic properties. 
(BL) Alcoholic extret :—Infusum is obtained to about 15% and decoctum 
about 10% of the bark. They are greasy, transparent and reddish brown 
substances and acidic, but they do not dissolve in water and give no reaction 
in the animal body. 
Material Animal. No. Weight | Mode of een Dosis Result 
Ethereal extract Guinea pig. No. 13 230. Emulsion, subcutaneously 0.02 Negative 
5 No. 17 250 2 a 0.20 = 
Alcoholic infusum > No. 14 190 we x 0.02 = 
= Rabbit. Noms: 2585 A 7 0.10 = 
Alcoholic decoctum 6 No. 2 |- 2435 - 5 0.10 es 
Remark: Materials injected were always neutralized with dilute solution 
of sodium carbonate. 
(©) Aqueous extract :—100 grams of the bark is shaken 3 times with 
cold water and then filtered. To this transparent extract acetic acid is added 
at the rate of 3%, then a flocky, slightly yellowish white subtance precipitates 
abundantly. After sucking and drying, we obtained 0.18 grams of light 
powder. ‘This substance (I) is soluble in water which becomes reddish brown. 
If we inject its neutralized aqueous solution into a Guinea-pig, the latter is 
affected with intoxication and the lethal dose is 0.1 gm. per 1 kilo. body 
weight. When the yellow, acid solution separated is treated with strong alcohol 
we again obtain a large quantity of flocky mass of white color. This substance 
(II) easily dissolves in water to a neutral reddish brown solution. It has 
