160 
ON PURE WHITE GUTTA PERCHA. 
BY F. BADEN BENGER. 
The demand for this substance, for dental purposes, is now sufficiently es¬ 
tablished to justify rue in making a feAV remarks on it and its preparation. 
I have examined specimens of the so-called pure white gutta percha ” now 
commonly sold, and find that for the most part they may have been designated 
almost as correctly “ pure white oxide of zinc,” being made up with this sub¬ 
stance in very large proportions, and I believe thereby rendered less tough, 
durable and fit for the purpose ; this opinion has been strengthened by the fact 
that persons to whom the pure and afterwards the commercial article have been 
supplied, have frequently complained of the inefficiency of the latter. I am 
further induced to describe the process I use, by the very high price required by 
makers of the really pure substance. 
A good sample of crude gutta percha will yield at least 75 per cent, of the 
pure resin. Some care should be taken to obtain a specimen with as little im¬ 
purity as possible. The bottle marked No. 1 contains some of the kind I find 
best; it is imported in roundish blocks, which are exceedingly hard and dif¬ 
ficult to cut, but any of the large gutta-percha manufacturers will supply 
the same torn into fragments similar to the accompanying specimen. Four 
ounces of this digested with 5 lbs. of methylated chloroform for a few days, 
will form a solution sufficiently fluid to filter through ordinary bibulous paper; 
this should be conducted in such a manner as to allow little or no loss of 
chloroform by evaporation, the apparatus for filtering volatile liquids described 
in Mohr and Redwood’s ‘ Pharmacy ’ answering the purpose ; the addition of 
another pound of chloroform rendering the filtration more expeditious. To 
the filtered solution, which should be bright and nearly colourless, add an 
equal bulk, or a sufficient quantity of spirit of wine to precipitate the gutta 
percha, which will separate from its solvent as a white bulky mass ; this should 
be rinsed with spirit, pressed in a cloth, and dried by exposure to the air, its 
condition is then that of the accompanying specimen, marked “ No. 2,” perfectly 
white, but too porous for dental use ; it should then be boiled for half an hour in 
a porcelain capsule and rolled in sticks whilst hot, as specimen u No. 3.” The 
chloroform can now be separated from the spirit by the addition of water, and 
lastly the spirit from the water by distillation, at the leisure of the operator. 
There is, therefore, no reason why the chemist should not prepare this sub¬ 
stance himself, and if he is careful to prevent the loss of chloroform and spirit 
in the process, its reduced cost and greater purity will compensate him for the 
trouble. 
A LETTER ON THE RELATION OF REMUNERATION TO 
PHARMACEUTICAL RESPONSIBILITY. 
BY R. W. GILES. 
The subject of pharmaceutical ethics, which, in its general aspect, was so 
ably brought before the Conference two years ago, at Nottingham, is naturally 
suggested for further consideration at the present time, in certain phases 
connected with the Pharmacy Amendment Act and also with a recent de¬ 
plorable catastrophe, which can scarcely be called an accident, resulting in the 
death of a young lady from this place by an improper dose of a most improper 
solution of strychnia. Regretting much that circumstances will not allow me 
