301 
EXTRACTS OF THE BRITISH PHARMACOPOEIA. 
any fresli discovery, it confirmed the fact first noticed by MM. Henry and 
Chalard, and subsequently by Dr. Christison, of the presence of hydrocyanic 
acid, under certain conditions, in bitter cassava root. The specimen of the 
juice now on the table, and the products obtained from it, would be conclu¬ 
sive evidence, he thought, to all present, of the presence of hydrocyanic acid. 
It was certainly a most interesting circumstance that a root which yielded 
such a mild nutritious substance as tapioca, should also yield so virulent a 
poison as hydrocyanic acid. It was also remarkable that sweet cassava root, 
which was obtained from a plant so closely allied to that yielding bitter 
cassava root, would not under any circumstances produce hydrocyanic acid. 
The bitter cassava and sweet cassava roots presented in these respects a 
striking similarity to bitter and sweet almond seeds. 
Dr. Edwards said that an analysis of the red earth alluded to in Dr. 
Daniell’s paper, and which had been regarded as an antidote to the poisonous 
principle of the root, was desirable. It would probably be found to contain 
an antidote to hydrocyanic acid, in the form of oxide of iron. 
Dr. Redwood thought that the author of the paper had left the question of 
the poisonous principle of bitter cassava root in a very unsatisfactory state. 
Iso information was given as to the quantity of hydrocyanic acid obtainable, 
nor any details as to the process adopted for the purpose. That hydrocyanic 
acid might be derived from bitter cassava root was clear, but how it was 
formed, was still a subject for investigation. Indeed, he thought that it had 
yet to be proved that hydrocyanic acid was the sole poisonous principle of the 
root. 
ON SOME OF THE EXTRACTS OF THE BRITISH PHARMA¬ 
COPOEIA PREPARED FROM THE DRY MATERIAL. 
BY A. F. HASELDEN. 
I .—Extract of Calumbo. 
The British Pharmacopoeia, which we were so anxiously looking for about 
this time last year, has now been in our possession nine months, and during 
that time it has been pretty freely commented upon by lecturers and others ; 
but in those cases there has been no discussion between the lecturers and 
their audiences, or the writers and their readers ; the talking, if one may so 
express it, has been all on one side of tl>e table ; now the opportunity for ex¬ 
perimenting and obtaining something lixe reliable results in making the vari¬ 
ous pharmaceutical preparations, has probably been limited, influenced by 
the number of the changes and the disposition to ignore the work, but there 
has been time for many of us to try our hands upon the British Pharmacopoeia 
dishes, and as there is abundance of material to work upon, I hope that my 
paper this evening will be but one of very many which will be contributed by 
the members and associates of the Pharmaceutical Society during the session. 
My present object is to bring before your notice some of the British Phar¬ 
macopoeia extracts prepared from the dry material, touching upon those 
points in the preparation which seem to require it, and offering as far as it 
goes the result of my own experience, and thus make as it were a starting- 
point for free discussion, not in a spirit of criticism, but with the intention of 
coming at a fair and useful conclusion. 
