340 
THE PHARMACEUTICAL JOURNAL AND TRANSACTIONS. [October 21,1871. 
end of the tincture press lever as equal practically to fifty 
pounds. Surely they would not have taken tbe force ap¬ 
plied as equivalent to fifty pounds only, had one hundred 
pounds been the actual power that could be used, for thereby 
they would have undervalued the power of a machine, the 
superiority of which over the screw tincture press they wished 
to show. 
In conclusion, I beg to assure Mr. Staples that nothing 
was further from my intention than the “ courteous sar¬ 
casm ” for which he gives me credit. 
Laboratory, M), Aldersyate Street. Chas. Umney. 
Sir,—When last week I wrote my reply to Mr. Umney, I 
had never computed the power of my own press. I was so 
satisfied at having obtained an implement that did its work 
well without much labour, yet so effectually that the marc 
appears as if dried, rather than only pressed, that I never 
troubled myself with any useless calculations about it, for 
they are but theoretical although giving a proximate estimate of 
mechanical force. The result led me to suppose that I had 
increased the power, but I never knew to what extent until 
Mr. Umney’s criticism (Pitarm. Jottrn. October 7th) induced 
me to measure and calculate it. I now beg most cordially to 
thank that gentleman for teaching me its value, for I am 
really astounded to find how far it surpasses that of the press 
in general use. In my original paper on the tincture-press 
{vide Piiarm. Jouen. September 9th) I supposed one yield¬ 
ing a theoretical pressure of nearly twenty tons. 100 lb. 
power being multiplied over 400 times, the figures were merely 
assumed for the convenience of illustration, as there stated. 
Nowl learn from Mr.Umney that in practice these implements 
are manufactured with such huge bulk of screw that the cal¬ 
culation only works out to about half this result. If then my 
estimate of twenty tons (theoretical) pressure from a good 
screw-press of the ordinary construction is so exaggerated, 
what will be said of the power of my press ? I feel some 
diffidence, almost hesitate to quote the figures, for fear that 
some of your readers, not working out the calculation, may 
think them fabulous; figures, however, like facts, are stubborn 
things. My press has two screws, the threads are one-eighth 
of an inch, with levers of seven inches radius, consequently 
each screw multiplies the power 7 x 6 * 8 = 336 times. As to 
the power, with all respect for Mr. Umney’s opinion, yet 
guided by that best of all teachers, my own experience, aided 
by the experience of others with whom I have conversed, also 
by the excellent authority of Professor Redwood ( £ Practical 
Pharmacy,’ p. 107), I continue to average at 100 lb., this 
would give a total for both screws of 336 x 100 x 2 = 67,200 lb., 
or thirty tons ! 
Now. if this result is obtained from an implement rudely 
constructed as a working-model, what may we expect from 
one of superior ■workmanship, with a further multiplication 
of power, which could be most effectually obtained by reduc¬ 
ing the screw-thread, and as this would also diminish friction, 
a double benefit would be obtained? In my paper (Phaem. 
Journ., September 9) I explained why it is impracticable to 
reduce the size of the screw in the ordinary press ; but in mine 
it can be safely reduced to any reasonable extent. No amount 
of power so applied can injure it, provided the cross-bar is 
kept in a nearly horizontal position by a turn or two of each 
screw alternately. We will suppose a press, constructed on 
ray model, with a pair of highly-finished steel screws, with 
threads one-twelfth of an inch, which should be cut deep into 
the rod so as to present an angle more acute than usual, say 
about 45°, with levers of 8 inches radius; this would multiply 
the power over a thousand times (8 x 6 x 12 = 576 for each 
screw), giving, with 100 lb., a theoretical pressure with greatly 
reduced friction of over fifty tons ! Such an implement would 
be convenient, portable and not expensive, yet giving a mag¬ 
nificent power, fully up to the requirements of the pharmaceu¬ 
tical laboratory, even if it did not entirely supersede the hy¬ 
draulic and all other presses; but these figures are but theore¬ 
tical. Now, I am a practical man, and would rather have a 
thing done than talked about; perhaps one of your readers 
now wanting a good screw-press will have one made as I 
suggest (I know it would prove a most profitable investment), 
and then put it to the test; let a gallon, say of tincture of 
orange peel, be made for actual use and pressed by it, and 
another gallon made at the same time and under similar cir¬ 
cumstances be pressed off by the best screw-press that can be 
obtained of the ordinary construction, and note the result, 
the measure of product in each case, weight of marc, also time, 
labour and trouble. This would be of more value than all the- 
theoretical calculation * or anything that could be said or 
written about it for the next twelvo months. 
October 1 6th, 1871. o. 4. Staples. 
E. H. S .—(1.) Pulvis Tragacanthoe Compositus is 
doubtedly intended. (2.) Ferrocyanide of Potassium is not 
a “poison” under either schedule of the Pharmacy Act, 1868. 
T. B .—Wanklyn and Chapman’s ‘Water Analysis’ (Triib- 
ner). 
J. B. B. —See a series of articles on the Cultivation of 
Medicinal Plants at Hitchin, Piiaem. Jouen., 2nd Series, 
Yol. I. pp. 275, 323, 414, 515. Also an article on the Culti¬ 
vation of Medicinal Plants at Mitcham, Phaem. Jottrn.,. 
2nd Series, Yol. YI. p. 256. 
“ A Minor Associate .”—(1.) Ung. Plumbi Subacet. Co. 
made as you state, does change from a yellowish colour at 
first to a white, and it afterwards assumes a bluish tint on 
the surface, but will be found white below. If made with 
almond oil, the ointment also soon gets a surface coating of 
an orange colour. We are unable to explain the causes of 
these discolorations. As the ointment quickly becomes rancid, 
it should not be kept long prepared. (2.) Camphor is de¬ 
structive to some parasitic growths, but that it has any further 
action as a “disinfectant” we very much doubt. (3.) Bran 
does contain albuminous matter, phosphates, etc., which are 
soluble to some extent when taken as food, but its action is 
generally considered to be mechanical. (4.) “ Species” should 
be translated “species.” You might label the ingredients 
“species for infusion.” 
“A West-End Chemist's ” letter is too personal for inser¬ 
tion. Would it not be better for him to inquire from the firm 
referred to what they really did charge ? 
L. S .—To make ten pills, the prescription sent may be 
readily dispensed thus :— 
R. Quin. Sulph. et P. Zingib. ana gr. x 
Ferri Sulph. Exsic. gr. vj (=gr. x of crystals) 
01. Menth. i^x. 
Adder P. Trag. Co. gr. iij. 
Syrupi Simp. tr\.x. 
Rub the sulphates to a fine powder; add the other dry in¬ 
gredients and the oil; lastly, the syrup. Mix well, and roll 
out quickly. 
“ Sempervirens” (Ryde).—(1.) Epilobium hirsutum. (2.) 
Mentha aquatica. 
G. B.—Milium effusum. The specimen was much broken. 
J. Bobbins (Bath).—Dr. Tilden’s “Notes to the Pharma¬ 
copoeia ” were commenced in this Journal, 2nd Series, Yol. XI. 
p. 654. 
B. A. —Dissolve the gallic acid in the aqua camph. made 
warm. Clear. 
“ Vectis .”—We agree, to some extent, with the opinion 
expressed in your letter, but think that its publication would 
be prejudicial to a matter of wider importance than that 
referred to. 
“ One who has Passed Fairly” should address the Secretary 
on the subject referred to in his letter. 
J. PL. D .—We should think such a person would be liable 
under the Medical Act as an unqualified person. 
J. W. Lasham. —Exemption from the duties referred te 
cannot be claimed. 
J. Bobbins (London).—The communication acknowledged 
in last week’s journal was from another Mr. Robbins. 
W. F. Caunt .—Elixir Proprietatis = Tinct. Aloes Comp, 
of the old London Pharmacopoeia. 
The following journals have been received:—The ‘British 
Medical Journal,’ Oct. 14; the ‘Medical Times and Gazette/ 
Oct. 14 ; the ‘ Lancet,’ Oct. 14; the ‘ Medical Press and Cir¬ 
cular,’ Oct. 18 ; ‘Nature,’ Oct. 12; the ‘Chemical News/ 
Oct. 14; ‘ English Mechanic,’ Oct. 13 ; ‘ Gardeners’ Chro¬ 
nicle,’ Oct. 14; the ‘Grocer/ Oct. 14; the ‘Journal of the 
Society of Arts,’ Oct. 14; the ‘Brewers’ Guardian/ Oct, 15; 
‘New York Druggists’ Circular’ for October; ‘Brighton 
Daily News;’ ‘Canadian Pharmaceutical Journal’ tor Oc¬ 
tober. 
Communications, Lettees, etc., have been received from 
T. Small, E. Agnew, R. Chubb, J. Abbott, A. Williams, J. 
Bairnsfather, Barnsley (Brazil), A. B. Daniell, W. M. Betts, 
J. T. Robinson, J. B. Barnes, T. A. S., X. Y. Z., “ Give and 
Take.” 
