266 
PHARMACEUTICAL MEETING. 
Mr. Mackay, of Edinburgh, understood from Mr. Proctor’s communication 
that he had used cacao butter in the composition of the suppositories, as ordered 
in the Pharmacopoeia. He (Mr. M.) had not been very successful with that 
material, but he had produced better specimens with a gun-metal mould than 
with one of pipe-clay. After reading Mr. Proctor’s paper in the Journal, he 
had again tried the use of cacao butter, but the result had not been such as he 
desired, the product being very liable to crack. Mr. Brady, to whom he had 
mentioned his difficulty, and from whom he had obtained the cacao butter, said 
he had never experienced this difficulty, but suggested the use of glycerine and 
water for facilitating the removal of the cones from the mould. 
Mr. Carteighe observed that different operators often obtained diffe¬ 
rent results. He had always been successful with metallic moulds. There was, 
perhaps, something in the use of a slippery liquid applied to the mould, and 
he had found soap liniment answer well; but even without any such appli¬ 
cation, if sufficient time were allowed for the material to cool and contract, 
he had never experienced any difficulty. 
A Member said he had been accustomed, in using metallic moulds, to hold 
the mould over a vessel of boiling-water, so as to allow the steam to condense 
upon it before putting the melted material into it, and this prevented adhesion. 
Mr. Martindale had found a mixture of glycerine and soft soap a good 
application to the mould. 
Dr. Attfield remarked on what had appeared to him a great merit in Mr. 
Proctor’s communications,—both the one just read, and that previously pub¬ 
lished in the Journal,—namely, that he effected his object with very simple and 
inexpensive materials. Thus, while one man required an expensive gun-metal 
mould, another could manage with a pill-box, a pair of scissors, a thimble, and 
a stick of sealing-wax. He could not help observing, however, that the speci¬ 
mens on the table were somewhat deficient in neatness of appearance.* 
ON THE PREPARATION OF MICROSCOPIC CRYSTALS. 
BY HENRY J. WADPINGTON. 
The subject of microscopic crystallography has been so often treated in various 
scientific journals, that the appearance of the present paper may appear some¬ 
what superfluous, but I think I may with confidence appeal to microscopists in 
general as to the insufficiency of what has been already written on this matter, 
much, indeed, of which has been but a repetition of what has preceded it; 
moreover, the end in view has more frequently been the production of crystal¬ 
line masses (I cannot call them crystals), which afford beautiful objects for the 
polariscope, than such as would be useful for the purposes of investigation or 
study. 
I think it may be laid down as a definite rule, that the formation of perfect 
crystals depends upon the rapidity with which they are deposited ; the more 
quickly solutions can be made to crystallize, the more perfect the crystals gene¬ 
rally are. 
The directions usually given are, to place a few drops of a cold saturated so¬ 
lution on a clean slide, and allow it to evaporate spontaneously ; but the result 
of this is unsatisfactory, compared to that obtained by allowing the crystals to 
deposit from a hot and concentrated solution. To take borax for an example, 
if a strong solution of this salt is made in hot distilled-water, the liquid filtered, 
* Mr. Proctor expressly stated, in sending the specimens, that they were only intended to 
show how suppositories could be made in the hurry of dispensing.—E d. Ph. J. 
