Jane 28, 18J3.) 
THE PHARMACEUTICAL JOURNAL AND TRANSACTIONS. 
1041 
■irmsaxtums of fire fipmatcutol Soeietjr. 
EXAMINATIONS IN LONDON. 
June 18th, 19£A, and 20 tlx, 1S73. 
Present—Messrs. Allchin, Barnes, Carteighe, Cracknell, 
Gale, Hills, Linford, Martin dale, Schweitzer, Southall, 
and Umney. 
Dr. Greenhow attended on the 20 th on behalf of the 
Privy Council. 
MAJOR EXAMINATION. 
Nine candidates were examined. Three failed. The 
following six passed, and were declared duly qualified to 
be registered as Pharmaceutical Chemists :— 
^*Cleaver, Edward Lawrance.London. 
*Plowman, Sydney.Boston. 
Woods, Joseph Henry.Warrington. 
Kirton, Christopher Henry.Hull. 
Woolldridge, George.Birmingham. 
Pound, Henry William.London. 
5ZZT MINOR EXAMINATION. 
Forty-eight candidates were examined. Twenty-Jive failed. 
The following twenty-three passed, and were declared duly 
qualified to be registered as Chemists and Druggists :— 
* Griffiths, F rancis.W eston-super-Mare. 
* Cotter ell, William Burbidge ...Dover. 
1 ( ^‘Griffiths, Edwin Harpham.Hanley. 
\ *Gwynne, David William .Swansea. 
Hitchcock, Edmund Lilley ...Oxford. 
Maynard, Henry Robert .Brandon. 
Gallier Robert .Tunbridge Wells. 
( DufFus, Alexander .London. 
£ l Vickery, Alice.Camberwell. 
'i < Holdgate, Arthur .King’s Lynn. 
I" c. Williamson, Thomas Umbers.. .Coventry. 
•2 ( Robinson, Edward Henry.Chichester. 
\ Thornton, Edward .Walsall. 
Adams, William.Barnstaple. 
Beverley, Robert Henry .Nottingham. 
Burman, Charles Clarke .Liverpool. 
Kemp, George. Birmingham. 
rt ( Marks, Frederick Comerford...Wantage. 
d (. Pitts, Thomas Cruso ..Norwich. 
Leach, Isaac .London. 
Bathe, William .Chippenham. 
Barritt, Frederick Allred .Croydon. 
Righton, James .Southport. 
The above names are arranged in order of merit. 
# Passed with Honours. 
LIVERPOOL CHEMISTS’ ASSOCIATION. 
The twelfth general meeting was held at the Royal 
Institution, May 8 th, 1873, the President, Mr. E. Davies, 
E.C.S., in the chair. 
Mr. Thomas Williams, F.C.S., called attention to the 
coating of paint which covers some of the canisters con¬ 
taining the preserved meat from South America and the 
colonies. The paint on one which he'had purchased con¬ 
tained red lead, and after having been carefully opened by 
the vendor, he found that 50 grains of red lead had got 
into the meat. 
In reply to an inquiry by Mr. Simpson, he said that 
there was no necessity to paint the tins, that they were 
painted after their arrival in this country, to give them a 
more saleable appearance. He found that only one firm 
used red lead, other tins being painted with silicate of 
iron paints, which were comparatively harmless. 
Mr. Taylor suggested that it would be better to lacquer 
the tins. 
Mr. J. Abraham then read the following paper :— 
Notes on Commercial Dilute Hydrocyanic Acid. 
The dilute hydrocyanic, commonly called prussic, acid of 
the Pharmacopoeia is composed of 2 parts of hydrocyanic 
acid and 98 of water. It is made by distilling together 
a solution of ferro-cyanide of potassium and a dilute 
sulphuric acid. The product is of uncertain strength, 
because the whole of the hydrocyanic acid is not neces¬ 
sarily condensed. The real relative quantity obtained must 
be ascertained, and the liquid made to correspond to the 
standard. The correctness of the preparation will depend 
upon the accuracy with which this is done. But, however 
carefully it may be accomplished, the resulting acid may 
afterwards be found defective. 
It is liable to decomposition, especially if exposed to 
light (though our Pharmacopoeia does not mention this), 
and to loss of strength by exposure to the air, owing to 
the greater volatility of the hydrocyanic acid than of the 
water. Especially must this be the case when the con¬ 
tents of a small bottle are used up by little and little 
during a considerable period of time. 
The strength of eight specimens procured from different 
sources, was ascertained by Dr. Tilden, and the result of 
his examination will be found in the Pharmaceutical 
Journal for July 29, 1871. His report exhibits a scale 
ranging in percentage of real acid from 2183 to 0183— 
four of the specimens being under 1 per cent .; the true 
standard, as I have mentioned before, being 2 . 
During the latter part of last year I obtained specimens 
of the acid from four wholesale houses, the percentage of 
real acid I found to be— 
2-11 
2-02 
1-64 
1-30 
instead of 2 . 
Compared with the pharmaceutical standard the 
strengths are :— 
105-5 'j 
101 - ( 
§ 2 - / per cent. 
65- ) 
This is not nearly so great a disparity as is exhibited 
by the table of Dr. Tilden, but it is so great that I think 
dispensing chemists should be put on their guard. 
The Pharmacopoeia says, that 100 grains of the acid pre¬ 
cipitated with a solution of nitrate of silver will yield 
10 grains of dry cyanide of silver. The application 
of this test requires time, for unless the precipitate 
be thoroughly washed and dried,—and nothing but time 
can ensure this,—it is delusive. Moreover you cannot 
safely diminish the quantity operated on, unless you em¬ 
ploy a delicate balance. The Pharmacopoeia gives a 
further and very beautiful volumetric test. We are told 
that 270 grains of the dilute acid, rendered alkaline by 
solution of soda, requires the addition of more than 1000 
grain measures of volumetric solution of nitrate of silver, 
before a permanent precipitate begins to form. If the 
acid under examination requires only 900 grain measures, 
then the strength is only aa of the proper strength—if it 
requires 1100 grain measures, then the strength is -i^, and 
so on. 
The experiment is directed to be performed by means 
of a burette, holding 1000 grains, divided into 100 equal 
parts ; but such quantities as these do not suit a dispenser 
who perhaps only buys an ounce or tw r o at a time, as is, 
I suppose, the case with many. The experiment may 
however be performed equally well with smaller quantities 
and appropriate instruments. 
This 100 grain tube filled as a Mobs’s burette enables 
me to experiment on quantities one-tenth of those named, 
and to obtain equally accurate results, because half a 
grain in this tube is as distinctly indicated as five grains in 
