December 9,1871.] 
THE PHARMACEUTICAL JOURNAL AND TRANSACTIONS. 
479 
Redwood had hit the blot in this paper. In the presence 
of morphia and other organic principles, the iodine 
would soon displace hydrogen and become invisible. 
The action of iodine on narceia was very peculiar. They 
were aware of the dark blue colour obtained by adding 
to it free iodine. On warming the liquid the colour dis¬ 
appears temporarily, and when it reappears is of much 
diminished intensity. Fresh iodine restores the colour. 
This series of reactions can be continued until iodine 
no longer produces a blue but a brown colour, like that 
of the periodides of the alkaloids generally. He could 
not help, however, expressing his admiration of Mr. 
Miller’s paper, whilst entertaining the opinion that it 
was not truly practical. He should be surprised if such 
a complicated process could be got through in two hours 
and a half. 
; Professor Redwood said it certainly could not be 
accomplished in that time if the drying were included. 
Mr. Groves, continuing, said that the processes for 
the estimation of morphia in opium were very numerous. 
He met with a new one every six months or so, but they 
all failed in one particular, viz. the long time required for 
carrying out the operation. He had thought of trying 
if Mohr’s method might not be modified, so as to be 
made alkalimetrical, and at the same time sufficiently 
accurate for trade pui’poses. The mixture of lime and 
opium is of such a texture as to be very readily ex¬ 
hausted with water; and if the amount of percolate were 
made a fixed quantity, he thought that the addition of a 
standard acid would indicate the quantity of the lime 
compound present, from which the quantity of morphia 
could be calculated, with, of course, certain corrections, 
such as experiment alone would point out. The rapidity 
obtainable by some such method would seem to j ustify a 
trial or two. 
Dr. Tilden said that he was under the impression 
that iodic acid had been quite condemned as a reagent 
tor morphia, simply because the reaction was not definite, 
and because iodic acid was similarly decomposed by 
other substances. They all knew what a complex body 
opium was. There were at least twenty-five different 
alkaloids described as having been derived from opium, 
and until the reaction of every one of these had been 
ascertained, he should question the accuracy of such a 
process. That objection would apply to any volumetric 
jrrocess for morphia, because it would be necessary to 
ascertain the reaction of the reagent on every one of 
those organic principles before the operator could be 
•sure that the reaction he was examining -was due en¬ 
tirely to morphia. 
Professor Attfield remarked that another important 
point, in addition to the action of iodic acid on the alka¬ 
loids of opium, was the action of the iodine that was set 
free on these alkaloids. Dr. Tilden had worked upon 
the question of the action of iodine on the alkaloids of 
opium and the formation of the periodides, and perhaps 
he could say something on that subject, confirmatory or 
otherwise, of what Mr. Miller had stated. 
Dr. Tilden said that iodine combined with nearly all the 
organic bases, decomposing one portion of them to form 
hydriodic acid, and forming compounds which in most 
cases seemed to be tri-iodides, consisting of a molecule of 
the alkaloid plus a molecule of hydriodic acid plus two 
atoms of iodine. Those compounds were perfectly definite 
and crystallizable substances, so that a certain portion 
of iodine might be disposed of in that way. It was 
possible that might account for the disappearance of 
some of the iodine. Disulphide of carbon would not 
be capable of removing iodine from such a compound, 
and so would not become coloured. The compounds 
wore not soluble in the disulphide. 
Professor Attfield said that Mr. Miller’s remarks 
were confirmatory of those now made by Dr. Tilden, 
with one exception. Air. Miller said that iodine water, 
when added to a slightly acid solution of papaverin, 
produced some sort of compound from which disulphide 
of carbon abstracted the iodine and liberated the papa¬ 
verin. That seemed to be an exception. It seemed to 
be the general rule that disulphide of carbon did not 
attack these combinations. 
The President gave a summary of the contents of a 
paper written by himself on “ The Syrup and Resin of 
Tolu, and Tincture of Cinnamon.” [This paper is 
printed at p. 467.] 
The meeting was adjourned to the 7th of February, 
1872. 
Dnutoimral Snmsiwtwns. 
LIVERPOOL CHEMISTS’ ASSOCIATION. 
The Fourth General Meeting of the Society was held 
on November 23rd; the President, Mr. E. Davies, 
F.C.S., in the chair. 
The following donations were announced:—Current 
numbers of the 1 Pharmaceutical Journal;’ the ‘Journal 
of the Liverpool Polytechnic Society;’ an ‘ Abstract of 
the Proceedings of the Liverpool Geological Society, 
1870-71;’ the ‘New York Druggists’ Circular;’ and 
‘ A Metric System of Arithmetic.’ 
Specimens of alum, illustrating Spence’s process of 
manufacture, were presented to the Museum by Mr. 
Williams. 
Mr. Abraham said that there had been lately in the 
Pharmaceutical Journal a good deal of correspondence 
respecting tincture presses, and as the subject seemed 
to have considerable interest, he would mention his 
experience with respect to them. He had for eighteen 
years used an hydraulic press made by Mr. Coffey, and 
found that it remained as good as new. The diameter 
of the ram was A£-inch, of the piston of the pump T V- 
inch, the area would therefore be as 36 to 1, and the 
lever would multiply the power twelve times. Alto¬ 
gether, the power of the hand would be multiplied 432 
times; and, supposing the pressure of the hand to be 
50 pounds, the press would raise about 10 tons. Messrs. 
Hayward, Tyler and Co. had introduced a compound press 
which was calculated to exert a pressure twice as great as 
this. But he did not find that the price of the hydraulic 
press had been reduced since he bought his. On the other 
hand, Mr. Staples had described a screw press, which 
was said to exert pressures as great as these. He did 
not question the possibility of this, but his preference 
for the hydraulic press was founded on the facility with 
which a moderate, gradually rising to a great, pressure 
coubl be applied. But if Mr. Staples’s press would bear 
the assumed pressure, any one who would look at the 
figures of it and of Messrs. Hayward’s, as well as of 
other hydraulic presses, would see that the strength of the 
latter was greatly in excess of the necessities of the case. 
In answer to observations by the Chairman and 
others, Mr. Abraham said that the form adopted by 
Messrs. Hayward involved a short ram which necessi¬ 
tated a screw over it, and added to the cost. Tlio 
force that all who had used the screw press knew to 
be required to reverse the movement, indicated the force 
which had to be overcome before any useful pressure 
could be applied by means of it. He did not think that 
the leakage ascribed to the hydraulic press interfered 
with its application as a tincture press, because what¬ 
ever press was used the tincture would soon cease to 
flow unless the pressure was renewed. He thought the hy¬ 
draulic press would invariably be preferred -were the price 
the same, and hoped that cheaper forms might bo devised. 
Mr. A. II. Mason, F.C.S., showed a specimen of Cun- 
durango. 
Dr. Charles Symes then read a paper, entitled “Ob¬ 
servations on Practical Pharmacy.” 
A discussion on the subject of the paper followed, in 
which the President, Messrs. Abraham, Blood, Bed¬ 
ford, Tanner and Armstrong took part. 
