344 
PHARMACEUTICAL MEETING. 
certain extent; but then I employ it in the best way, and yet only as much as 
I am fully justified in doing. Now, if this make-up quantity of fluid was 
added at the commencement of the macerating part of the process, I should not 
obtain the same result; the effect of percolating an extra ten, fifteen, or twenty 
ounces, as the case may be, through the ingredients now pretty well packed, 
does much more towards exhausting them and clearing off any adhering extrac¬ 
tive, before pressing, than simply soaking them with the additional quantity of 
fluid during maceration. I can also, and do, in my apparatus press considerably, 
by means of weights placed on the material and within the vessel, before re¬ 
moving to be again pressed in the ordinary way. To continue : with compound 
tincture of cardamoms, the loss in bulk is very trifling, in consequence of the 
saccharine matter obtained from the raisins, and from the unabsorbing nature of 
the other ingredients. In some of the tinctures there is no loss in bulk, or 
rather the required quantity is obtained without any additional fluid ; and 
these have been pointed out in the last edition of the B. P. In the tincture of 
hop, and simple and compound tincture of bark, the loss of the menstruum is 
often as much as sixteen and eighteen fluid ounces in the gallon; in the two 
bark tinctures, the quantity of solid matter to be acted upon being above the 
average,—the average being two and a half ounces to the pint, whereas in the 
compound tincture of bark it is 3| oz. -f 90 grains or nearly 3f oz., and in the 
simple four ounces. In these particular cases I am satisfied that exhaustion 
does not take place usually, but that the passing of the additional liquid 
eventually required to make up the proper measure does materially help it; 
but in these two last, the simple, more effectually true percolation, if well per¬ 
formed, I consider a mode of proceeding superior to that of the Pharmacopoeia, 
though I find the loss of spirit equal. It would be difficult to fix the loss ex¬ 
perienced by all workers at exactly the same figure, because the larger the 
quantity prepared, and the more perfect and powerful the pressure employed, 
as in wholesale establishments, the less in proportion will be the loss; but in 
retail establishments of average capabilities I think I am not far wrong as to 
the amount I have stated. I had occasion very recently to make some commer¬ 
cial tincture of rhubarb after my own plan, and in the vessel before spoken of ; 
and, as on former occasions, I had every reason to be satisfied with the quantity 
and quality of the product and the exhaustion of the marc. One word upon 
proof spirit and I have done. Five of spirit and three of water are the propor¬ 
tions by measure required ; but when mixed and allowed to stand, as you all 
know, a perceptible diminution in bulk takes place. For instance, with five 
pints or one hundred ounces of spirit and three pints or sixty ounces of water, 
speaking in round numbers, there will be, at 60° F., a diminution in bulk amount¬ 
ing to four ounces; this should be made up either by water or spirit, provided 
the mixture retains the specific gravity of *920. In other words, to be correct 
in the quantity of proof spirit used in making tinctures, it should not be mixed 
at the moment it is wanted, but should be kept ready for use. Although, to 
some minds, all that I have said may seem a very simple matter, I trust that 
I have shown that the spirit now simply ordered to be added may be more 
satisfactorily and usefully applied; that better products will result; and that 
the preparation of tinctures may still find food for discussion. Also, which per¬ 
haps is more important still, that by communicating freely with each other, and 
reporting our experiences, we do that which every true lover of his profession 
should and will do, and which no book could be expected to do for us. 
Mr. Bland remarked, that a manufacturer who would bring out a tolerably 
efficient press at a moderate price, which would place it within the reach of 
ordinary retail pharmaceutists, would be very much entitled to their grati¬ 
tude. 
