50 ODOROGRAPHIA. 
acid, sp. gr. 1°38, and four volumes of water, then neutralized 
with caustic soda and boiled in order to remove unattacked cymene 
and nitro-products, It is then precipitated with hydrochloric acid 
and the precipitate freed from nitroparatoluic acid &c. by boiling 
with tin and hydrochloric acid. The product always contains 
terephthalic acid, which remains behind on treatment with water. 
The paratoluic acid is finally purified by distillation with steam *. 
Paratoluy] chloride is next prepared, and this is heated with sodium 
salicylate. A viscid mass of paratoluylsalicylic acid, resembling 
turpentine, is formed, and decomposes into phenyl paratoluate and 
carbon dioxide on distillation with lime. It forms white plates, 
which have a nacreous lustre, smell like geranium, and melt at 
71°-72°+. The methyl and ethyl paratoluates are also fragrant. 
Phenyl benzoate.—Benzoyl chloride is first obtained by the 
action of dry chlorine on pure oil of bitter almonds, It is a 
transparent liquid, the vapour of which violently attacks the eyes, 
and has a peculiar, very penetrating odour resembling the sharp 
smell of horseradish. When benzoyl chloride is heated with 
phenol until hydrochloric acid ceases to be evolved, phenylbenzoate 
is formed. It is readily soluble in alcohol and ether, and crystal- 
lizes from a mixture of these in lustrous, monoclinic prisms, which 
melt at 71° and sublime at a higher temperature. In odour it 
resembles that of geranium f{. 
Methyl benzoate (“ Niobe essence’’) is afterwards described. 
The investigations made on “ grass oils ” by F. D. Dodge at the 
Organic Laboratory, School of Mines, New York (1889), are 
interesting as regards the rose and geranium odours, especially 
as the grass oils are procurable at their place of production in 
unlimited quantities. The following abstract of his paper on oil 
of Citronella refers to the Rose odour. 
Citronellic aldehyde.—Oil of Andropogon Nardus is shaken for 
ten minutes with a saturated solution of sodium bisulphite. The 
liquid solidifies into a white magma with considerable evolution of 
heat ; the vessel should therefore be kept cool withice. The pre- 
cipitate is wrapped in flannel, and after draining on a large funnel 
is carefully pressed in a filter press, thinned with ether or chloro- 
* Ann, Chem. Pharm. clxii. p. 539, and ibid. ecv, p. 118. 
+ Chem, Centralbl. 1859, p. 84. 
t Jahresber. 1879, p. 675, 
