412 
Proceedings of the Royal Society 
Calculated. 
Observed, 
II. III. 
0,6 192 55-5 
18 5-2 
Ca 40 11-3 
0, 96 28-0 
10-9 11-18 
346 100-0 
The silver salt forms small, indistinct, white scales, soluble in 
boiling water. The copper salt is a bright green amorphous pre- 
cipitate. The ferric salt, a pale brown precipitate, exactly like the 
ferric benzoate. 
The acid resists the action of dilute sulphuric acid and bichromate 
of potash, even when boiled ; when heated with strong sulphuric 
acid and bichromate it is oxidised, and gives off the smell of oil of 
bitter almonds. Fuming nitric acid readily dissolves the acid 
when heated, the solution becoming at first red, then colourless, 
and on cooling, a nitro-acid crystallises out. This nitro-acid forms 
colourless crystals, which dissolve in solutions of the alkalies with 
a yellow colour. I am at present engaged in its examination, and 
hope to obtain from it the corresponding amido- and oxy-acids. 
A comparison of the properties of the toluic acid thus prepared 
from mandelic acid with those of Moller and Strecker’s alpha-toluic 
acid from vulpic acid,* leaves no doubt of their identity. The fusing 
point of alpha-toluic acid is 76-5, that of the acid from mandelic 
acid is 76°-0; the former boils at 265° 5, the latter at 264°. All 
the characters of alpha-toluic acid, with the exception of the smell, 
are so exactly the same as those of the acid from mandelic acid, 
that there is not a word in Moller and Strecker’s description of the 
former which does not perfectly apply to the latter. 
The reduction of mandelic acid to alpha-toluic acid appears to 
prove, Is^, that, notwithstanding its lower fusing point, the latter 
acid is the true homologue of benzoic acid.f 
2d, That the reduction of the oxy-acids to the normal acids by 
the action of hydriodic acid is not peculiar to the fatty series, and 
* Ann. Ch. Pliarm. cxiii. 56. 
t The irregularity in the fusing point is not surprising, considering that 
benzoic acid is probably the first term in the series, and that a similar irre- 
gularity is observed in the case of the lower terms of the series of fatty acids. 
