260 ODOROGRAPHIA. 
concentrated sulphuric acid, chloroform added and the whole 
shaken. In the presence of benzoin or storax, the chloroform is 
coloured violet to blue. It is stated that by this method even 
small admixtures of these substances can be detected with cer- 
tainty, and it is affirmed that although, like the petroleum spirit 
and nitric acid test of the German Pharmacopeeia, it is dependent 
upon a colour reaction, it is more certain in its indications. 
The method of detecting castor oil proposed by Wagner is to 
expose a small portion of the suspected balsam to distillation until 
somewhat more than one half has passed; to shake the distillate 
with baryta water, to remove by means of a pipette the layer of 
oil floating on the surface, and to shake this with a concentrated 
solution of sodium bisulphite. If castor oil be present the liquid 
will immediately become a crystalline mass *. 
The United States Dispensatory gives the following test :—If 
one volume of the balsam be triturated with two volumes of sul- 
phuric acid, a tough, homogeneous cherry-red mixture should 
result. If this be washed after a few minutes with cold water, it 
should be converted into a resinous mass which is brittle when 
cold. 
A mixture of three parts of the balsam with one part of carbon 
disulphide remains clear, but a mixture of one part of the balsam 
with three parts of carbon disulphide separates from the balsam 
about 40 per cent. of resin. The liquid poured off from the latter 
should be transparent, should not have a deeper colour than light 
brownish, and should not exhibit more than a faint fluorescence. 
When distilled with 200 times its weight of water, no volatile oil 
should pass over. 
There sometimes exudes spontaneously from the trees a guin 
resin of a feebly bitter taste and entirely devoid of balsamic odour ; 
Attfield’s analysis of this substance shows it to contain 77°4 per 
cent. of non-aromatic resin, without a trace of cinnamic acid, and 
entirely different from the Balsam Peru. The leaves of the tree 
contain a fragrant oil. 
“ White Balsam Peru,” “ Balsamo Blanco,” or “ Baume Blanc 
de Son Sonaté” is obtained by pressure from the fruit-pods of 
Myrozylon Pereire. It has no similarity whatever to the balsam 
obtained from the trunk of the tree. In appearance it resembies 
* Am. Journ. Pharm, xxx. p. 570. 
