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BRITISH PHARMACEUTICAL CONFERENCE. 
of water upon those substances. They considered these products as having been in 
the original material; but in this they might be mistaken. Again, the chemistry of 
the present day consisted of observations of the action and reaction of one body upon 
the other within a limited range of temperature. For instance, we knew that hydrogen 
and oxygen when lighted gave water ; but that at a higher temperature the two united 
less easily; while, on the application of a still higher degree of heat, water decomposed 
and gave hydrogen and oxygen. These experiments should serve to remind us that we 
were dealing with natural facts only under a set of circumstances, and that the che¬ 
mistry of matter under different circumstances might be another thing altogether. 
Some discussion upon the nomenclature adopted took place. 
Mr. Brady remarked that he was glad to find the paper explained certain discre¬ 
pancies about meconine, since no two authors agreed upon the quantity of this principle 
present in opium. He also alluded to the method adopted by Mr. Deane and himself 
when engaged upon the micro-chemical investigation of opium. By way of checking 
their results, they prepared synthetically factitious opium. 
The President took cognizance of Dr. Fliickiger’s statement that he found 20 per 
cent, or more of morphia, a quantity which was much larger than the makers of morphia 
were willing to admit as attainable. 
Mr. Deane had rarely found so much as 20 per cent, of morphia. He thought that 
some standard of strength should be adopted for opium, and would suggest that none 
containing less than 10 per cent, ought to be used for making the tincture. 
NOTE ON AN IMPROVED DIFFERENTIAL THERMOMETER. 
BY J. C. BROUGH, F.C.S. 
As many members of the British. Pharmaceutical Conference are connected 
with local scientific associations, I may be excused for calling attention to 
Dr. Matthiessen’s ingenious modification of Leslie’s Differential Thermometer, 
which is now employed by our leading chemists and physicists as a means of 
illustrating experimentally in the lecture-room many fundamental points 
relating to heat. The bulbs in this instrument are pendent, and can there¬ 
fore be readily immersed in water; whereas in the ordinary differential ther- 
