498 TINCTURES AND WINES OF THE BRITISH PHARMACOPEIA. 
What is called “ English croton oil ” is pressed in this country from im¬ 
ported seeds. Very little oil is so made at present, on account of the trouble 
in preparing it. There is much difference in the appearance and character of 
samples, even from the same case or package. One will remain fluid at a low- 
temperature, and another will set speedily into a pasty mass. This may be 
partly due to the mode of pressing, whether cold or hot, as some oils pressed 
hot from the seeds or nuts will be harder than oil pressed cold from similar 
seeds. This has been proved by careful experiments on cocoa-nut oil. It is 
believed also that some croton is made by pressure and other samples by boil¬ 
ing the seeds which have been first stripped of their outer skin or husk. This 
may affect considerably both the melting-point of the oil, and also its chemi¬ 
cal character, since resinous substances may be brought out in one case and 
not in another. Similar differences as to melting-points are found in castor 
oils, and it is not always easy to equalize them even by filtration at the same 
temperature, as some oils will carry with them more stearine than others. 
This, my informant knows to be the case, from his own experience in oils. If 
two oils were cooled and filtered alike, one of which is quite neutral, and the 
other partly acidified, the latter would be more fluid after filtration than the 
other. The neutral stearines do not crystallize freely like the acid hard fats. 
They usually form masses of fine hair-like crystals, which do not separate 
readily from the oily part, so that a certain proportion will pass through with 
the oil. The acid fats crystallize out in the form of hard plates or con¬ 
cretions, which bear handling without breaking down, and can be completely 
separated by filtration. 
Again, if two oils pressed from the seeds were packed, one quite clean, 
and the other more or less contaminated with gum or mucilage, the latter would 
become more or less acidified, the gum, etc., apparently fermenting, and then 
setting up an acidifying action in the oil. This may explain some of the dif¬ 
ferences in the working and character of oils. 
Such being the accidents to which commercial oils are liable, I cannot 
wonder at variations in. their cohesion figures, but I do very much wonder 
that twelve different samples of castor oil should have given figures so much 
alike as in every case to enable a practised operator to identify the oil, and 
also, in the case of four specimens of croton oil, one of them solid at ordinary 
temperatures, all the figures should have a resemblance sufficient for their 
identification. 
THE TINCTURES AND WINES OE THE BRITISH PHARMACO¬ 
PEIA COMPARED WITH THOSE OE THE LONDON, EDIN¬ 
BURGH, AND DUBLIN PHARMACOPEIAS. 
BY DR. C. ULRICH. 
Wlien the * British Pharmacopoeia ’ came out, I found it a great help to be 
able at a glance to compare the strengths of the tinctures and wines of the old 
Pharmacopoeias with the new. To facilitate that purpose I have compiled the 
following tables, in which the solid ingredients used for preparing the tinctures 
and wines are brought out in grains, the dissolving medium being always one 
pint. The tables will be easily understood without any further explanation. 
As regards the opium preparations, it should be borne in mind that opium 
loses on an average 15 per cent, of water in drying, and that therefore 85 parts 
of the powder are equal to 100 parts of crude opium. 
