420 
THE PHARMACEUTICAL JOURNAL AND TRANSACTIONS. [November 18,1871. 
must be securely fixed; secondly, the threads of the screw 
must be stout enough to withstand the pressure; and lastly, 
the rod bearing the screw must be stiff enough to resist tor¬ 
sion. I grant that, by applying the power to the nut and 
not to the screw-head, the tendency to twist is greatly dimi¬ 
nished ; nevertheless, the friction of the metal surfaces (with¬ 
out which the screw would be useless, as it would run back 
directly the hands were removed from the handle) must pro¬ 
duce a considerable strain of that kind. Mr. Staples would, 
I think, be disillusionized as to the power of his press, were 
he to test the endurance of his wooden cross-beam E. It 
obviously is unable to bear anything like the pressure credited 
to it. Mr. S. has satisfactorily cleared up the doubt some 
appear to have entertained as to the superior efficacy of two 
screws over one. 
The idea of interposing a spring between the screw and 
the marc to be pressed, is, I think, a good one. A metal 
spring, however, could not be obtained of sufficient strength 
without incurring great expense. I propose trying the fol¬ 
lowing :—A cylindrical box of iron, about 4 inches deep, and 
of a diameter equal to the press-body, will contain an india- 
rubber bag that exactly fits it; on this will be placed a strong 
cover, thick enough to stand the force of the screw, and 
having guides on its side to prevent it tilting. It will have 
to be turned in a lathe so as to exactly fit the cylinder and 
offer no crevice for the india-rubber to be forced into when 
under pressure. The air contained in the bag will, of course, 
be the spring, and being permanently elastic, be capable of 
sustaining any amount of force one can put upon it. Prac¬ 
tical difficulties will, I suppose, crop up. I look forward with 
apprehension to the bursting of the cylinder, leakiness of the 
bag, etc. However, should I try it, I will candidly report 
results. 
There can be no doubt of the advantage that would be 
gained by giving to the pressure a degree of permanence, 
and to attain it is worthy of an effort. 
I have a press constructed like a cheese-press, except that 
its lever is compound. The nominal pressure exerted by it is 
6 tons. As the weights descend they are raised again by a screw 
and lever. In some respects it is useful, but I found that its 
power was far inferior to that of my large press with lever 
of 14-inch radius and screw-threads half an inch apart. The 
iron cross head or nut of this press I may mention is 3 inches 
deep in the centre, and is the third that lias been fitted to it; 
the previous ones having been unequal to the occasion. This 
perhaps is accounted for by its having sometimes to submit to 
the united forces of two strong men, who would together 
exert a force of at least 350 pounds. 
The compound hydraulic press of Desgoffe, a very useful 
and ingenious machine, is, I fear, too expensive for the ordi¬ 
nary retail druggist. I have often had it in my mind to adapt 
to the ordinary press some means for giving the marc a final 
pinch at the end of the operation. Hunter’s differential 
screw, worked by means of a powerful lever and advancing 
one-sixteenth of an inch each revolution, would give a very 
powerful pressure, and would, doubtless, be cheaper to con¬ 
struct originally and less liable to get out of order than a 
hydraulic arrangement. 
The fact, often lost sight of, that the intensity of the pres¬ 
sure exerted is proportional to the area over which it is spread, 
—so that, other things being equal, the intensity is doubled 
by the area being reduced to one-half, and vice versa ,— 
enables one to achieve, when desired, a more complete ex¬ 
haustion of the marc, and tends to equalize the power of 
large and small presses. 
Thomas B. (Troyes. 
The Chloral Controversy. 
Sir,—Tour remarks on chloral are interesting: the quantity 
given (half a ton) would not amount to more than about half an 
ounce to each of the 20,000 practitioners in Great Britain and 
Ireland; this the Echo refused to state. I find this paragraph 
as to a Lunatic Asylum in one of the journals, “ The amount 
used is ninety pounds in 370 cases! In one case 20-grain 
closes were given for 257 consecutive nights, with the happy 
result of securing refreshing sleep; the patient recovered.” 
We need scarcely require then the extraordinary conjecture 
of the Echo, that as chloral is cheaper than cocculus indicus, 
the chemists and brewers arc in league to supply it in tons 
to our beer and ale shops! 
Charles Kidd, M.D. 
Sir,—Although much has been said respecting this remark¬ 
able substance, doctors seem as little likely to agree respect¬ 
ing its properties as ever. 
A case in point may serve as a comment upon its alleged 
cumulative power. A gentleman, for whom I recently dis¬ 
pensed, took nightly at 9 p.M. 35 grains, and at 3 a.m. 45- 
grains of the crystalline salt during the space of nearly three 
"•months. 
If the opinion held by some authorities be correct, the man 
ought to have died long since; instead of which, his medical 
attendants report that the case is progressing favourably. 
Some misconception seems to exist as to the quantity of 
chloral hydrate actually made; but the consumption must, of 
necessity, be very large if the above-cited case is to be taken 
as an average. 
Australia alone consumes a large proportion of what is- 
exported from this country. 
R. Goodwin Mumbray. 
Richmond, S.JJ r ., Nov. loth, 1871. 
Spurious Specimen op Hemlock Fruit. 
Sir,—While preparing for the Minor examination, a short 
time ago, I had occasion to make use of a collection of Materia 
Medica specimens, which had been supplied by a first-class 
wholesale house. 
In going over the various specimens it contained, I came- 
upon a parcel labelled “ Conii Fructus,” which, on examina¬ 
tion, proved to be spurious, as it consisted almost entirely of 
other umbelliferous fruits, there being only a very few hem¬ 
lock fruits intermixed. I have the parcel still in my posses¬ 
sion. The greater portion appears to be the fruit of a species 
of Caucalis ( Torilis ), as it has a decided parsley taste, and is 
remarkably bristly, some of the bristles being hooked. 
I enclose a specimen for recognition. 
Such an occurrence ought to enforce on all engaged in the 
business the value of an intimate acquaintance with the several 
articles of the Materia Medica; and should also suggest the 
necessity of carefully examining all purchases of drugs, etc., 
no matter from what source they may be procured. 
Belfast, November 12>th, 1871. Thomas Green. 
[*#* The parcel of umbelliferous fruits sent by our corre¬ 
spondent contains a mixture of three different genera at 
least. The proportion of Conium fruits is very low, the bulk 
being composed of the spiny fruits of a species of Caucalis, 
near C. macrocarpa .— Ed. Pharm. Journ.] 
Difficulties in Dispensing. 
Sir,—In Mr. Wilkinson’s paper, published in last week’s 
Journal, I find the recommendation of a most objectionable 
practice unchallenged by the meeting before which it was 
given. 
The practice is that of making material alteration in a pre¬ 
scription without the sanction or the knowledge of the phy¬ 
sician; such as omitting a portion of an active ingredient 
altogether, or substituting for it another of different power. 
I am morb especially led to draw your attention to the 
matter, as in each of the cases given no such difficulty exists 
as to render the change necessary. 
Stockton, November 11th, 1871. T. B. 
Erratum -.—We are requested by the Hon. Secretary of the 
Leeds Chemists’ Association to make the following correc¬ 
tions :—In the report of the annual meting of that Society, 
ante, p. 347, col. 1, 1.36, for “party influence” read “parlia¬ 
mentary influence.” 
C. Gerring .—Rub the turpentine with the yolk of egg in 
a mortar, add rose water as required, transfer to a bottle and 
shake with the acetic acid, then gradually add the remainder 
of the rose water. 
W. Owen .—Rub the acetate of morphia with the glycerine, 
and add to the oil and chloroform previously mixed. 
“ Juniperus Sabina .”—The specimens forwarded are all 
from Juniperus Sabina. 
Communications, Letters, etc., have been received from 
Mr. J. R. Jackson, Dr. De Vrij, Mr. M. C. Cooke, Mr. F. 
Wheeler, Mr. David, Mr. W. Bates, Mr. W. S. Brown, Mr. 
S. Payne, H. E. R., T. B. 
