332 
POISONOUS PRINCIPLE OP BITTER CASSAVA ROOT. 
with, the known weight of chlorine from the whole quantity used, the differ¬ 
ence, calculated for nitric acid, gave a total of 63 grains,—B. P. strength. 
Allowing 2 grains for impurity of the iron, the above figures give the fol¬ 
lowing as the composition of this sample of Liquor Ferri Percliloridi :— 
Percliloride of Iron. 2521 grains. 
Pernitrate of Iron.17 „ 
Nitric Acid, 3110,2N 0 5 .... 47 „ 
Water, sufficient to make up ... 10 fluid ounces. 
If the process be less carefully performed, the amount of free acid will of 
course be less and that of the pernitrate of iron greater than in this instance. 
But the presence of a little of this last salt cannot, I presume, be reckoned 
of much consequence, as, according to Pereira, “ altogether this preparation 
resembles in its medicinal properties the sesquichloride of iron.” 
The tincture made with this liquor is similar in appearance to a good sam¬ 
ple of the P. L. preparation. The colour is, however, a shade lighter and the 
taste perceptibly more acid. 
I>r. Attfield, it appears, advocates the use of the anhydrous perchloride, and 
considers its preparation a very simple matter ; and so, no doubt, it is to a good 
manipulator, but I suspect that many of us would find it rather a troublesome 
business. If great purity were the sole desideratum, it would perhaps be the 
best plan ; but as a 'pharmaceutical process, that of the Pharmacopoeia seems 
to me to deserve the preference. Only the simplest apparatus is needed 
for its performance, and by the exercise of a small amount of care and skill it 
yields a product of uniform strength, and, to borrow a phrase from the last- 
named gentleman, “ sufficiently pure as a medicinal remedy.” 
[Respectfully yours, 
John T. Miller. 
Sheffield, October 19, 1864. 
POISONOUS PRINCIPLE OP BITTER CASSAVA ROOT. 
TO THE EDITOR OF THE PHARMACEUTICAL JOURNAL. 
Sir,—On my return from the Pharmaceutical Meeting on Wednesday 
evening, I turned to Gray’s Supplement, 5th edition, 1831, page 39, and 
found— 
“ Bitter Cassava (Jatropha Manihot ) root, full of an acrid, poisonous, 
milky juice, separable by expression, or corrected by roasting, thus yielding 
a nutritive farina; also by boiling the juice, which is used as a sauce and 
made into soy.” 
Beasley’s ‘ Pocket Formulary ’ mentions this sauce under the name of 
Cassareep. 
Royle says the juice is acrid and poisonous, owing, it is said, to the pre¬ 
sence of hydrocyanic acid, and probably also to an acrid principle. 
Gray’s testimony seems to favour the idea that the only active matter pre¬ 
sent in the bitter cassava-root juice is the hydrocyanic acid, unless the acrid 
principle is also poisonous and dissipated by boiling. While a chemical 
analysis of this root and the red earth spoken of by Dr. Daniell will doubt¬ 
less be very instructive and interesting, we cannot dissemble the fact that the 
chemistry of organic substances, so far as that science is treated of in our 
schools, is a very finite affair, and for medicine sadly wants associating with 
physiological tests to be really useful to the medical practitioner; and, to ad- 
