— 119 — 
apparent after 30 minutes by slight twitchings after stimulation. Tetanus did 
not occur. When 5 hours after the first injection (i. e. of the acetyl compound) 
the action of the strychnine had again almost disappeared, another injection 
was made with 0,000025 g strychnine. After this injection also only con- 
vulsions occurred, but no tetanus. 18 hours after injection of the ester the 
frog was found dead. 
It appears from these experiments, that the action of 
the acetyl compound of methyl ester of anthranilic acid is 
similar to that of anthranilic acid. After a few inco-ordin- 
ate movements, paralysis of the central nervous system 
occurs, which is not completely removed even by large doses 
of strychnine. The fatal dose, of which the quantity does 
not appear to be affected by strychnine, amounts to about 
1,0 g per kilogram weight of the frog. 
While the frogs were being dissected (experiments No. i, 3 and 4), 
an intense and penetrating odour of orange flowers was emitted from 
the portions of the body. The urine of the frogs which survived the 
injection, possessed the same characteristic aromatic odour. From the 
ether, with which a few cc urine of the frogs was repeatedly extracted, 
no crystals of methyl ester of acetyl anthranilic acid could 
be obtained. The compound consequently is split up 
completely in the organism of the frog into acetic acid and 
methyl anthranilate, the presence of which is revealed by 
its peculiar aromatic odour. 
Experiments No. 9 and 10. On rabbits and dogs (of medium size) doses 
of 1,0 g methyl ester of acetyl anthranilic acid, in oil emulsion, had no effect. 
Sugar and albumin were not detected in the urine. On account of the strong 
odour proper to the urine, an aromatic odour like orange -flowers could not 
be determined with certainty. 
As methyl ester of anthranilic acid, as a primary aromatic base, forms 
azo-dyes, this property can be made use of for purposes of demonstration. The 
dye has a yellow-red colour, is insoluble in water, but dissolves in concentrated 
sulphuric acid with a deep violet colour. The insolubility of the dye in water 
permits a quantitative estimation of methyl ester of anthranilic acid in solutions 
and in essential oils. For this purpose a definite quantity of the diazotised 
solution of methyl ester of anthranilic acid is titrated with an alkaline solution 
of y^-naphthol, when the dye thereby produced is precipitated. The litmus test 
shows whether the reaction is completed. 
In accordance with Erdmann's method [comp.BerlinerBerichte35 (1902)24] 
^'5 g /^-naphthol, purified by crystallisation from hot water, was dissolved in 
0,5 cc soda liquor and 150 cc water with the addition of 15 g sodium carbonate. 
A portion of the urine obtained from the rabbits was acidified with hydro- 
chloric acid, and diazotised at a low temperature with a 5 per cent, solution 
of nitrite. When, after a few minutes, free nitrous acid could be detected by 
means of potassium iodide and starch paper, a measured quantity of the 
/5-naphthol solution was titrated with this urine. After a few minutes a dark-red 
colouring -matter appeared, which, however, was not precipitated, but, on the 
contrary, dissolved immediately. It is quite possible that the solubility of the 
azo-dye was due to the presence of ammonia. Although this method therefore 
