SCIENTIFIC SUMMARY. 
427 
292 : 100. 318 : 100. 3rd set, 288 : 100. 335 : 100. 4th set, 300 : 100, 
hurst. 5th set, 384 : 100. 407 : 100. 482 : 100. 6th set, 242 : 100.” 
A nev) Process for the Manufacture of luhite Lead has recently been devised 
by M, A. Girard : — The lead is first prepared for treatment by granulating 
it the granulated metal is placed in a rotating cask (which should he made 
of beech or elm, not oak) with one-fourth its weight of pure water. The 
cask is made to rotate at the rate of thirty or fort}’- turns a minute, and ar- 
rangements are made for the passage of a current of air during the rotation. 
After about two hours, nearly the whole of the lead is found to be oxidised, 
and then carbonic acid is introduced in the place of the current of air, and 
the rotation continued for four or five hours further. At the end of this 
time nearly the whole of the lead is found to he converted into hydrated 
carbonate, fine white lead, which can he separated from all the metal re- 
maining intact by decantation. — Vide Chemical News, July 3. 
Impure Sulphate of Ammonia. — At the Norwich meeting of the British 
Association, Dr. T. L. Phipson read a paper on Sulphocyanide of Ammo- 
nium, in which he pointed out a fact of some importance to agriculturists. 
Dr. Phipson stated that for many years past the ordinary sulphate of am- 
monia manufactured in gas works by neutralising gas liquor with sulphuric 
acid contained small quantities of sulphocyanide of ammonium, say from 2 
to 4 per cent, j but latterly many specimens of commercial sulphate of am- 
monia contained a very much larger proportion, some specimens yielding as 
much as even 75 per cent, of sulphocyanide. So that, in fact, the article 
might rather he named impure sulphocyanide of ammonium than sulphate 
of ammonia. The knowledge of this fact is of great importance to makers 
of chemical manures and farmers, inasmuch as only one-half of the nitrogen 
existing in sulphocyanide can he made available for manuring purposes. 
The Acetifcation of Alcohol. — It has been frequently found by vinegar 
makers, says the Chemical News, that the acetification of alcohol in the 
casks does not proceed uniformly, and that on this account the strength of 
the acid manufactured varies considerably. To facilitate oxidation, M. 
Aldus dissolves 15 grammes of dry chloride of platinum in 2-5 kilogrammes 
of alcohol, and in the solution places 1‘5 kilogramme of wood charcoal 
in pieces of the size of a nut ; he then calcines in a covered crucible. 
This done, he takes 0 75 kilogramme of platinised carbon, and strews 
it upon a wooden cover pierced with holes, placed over the open top of a 
vinegar cask, 2 metres in height and of from 0'80 m. to 0‘90 m. in 
diameter j the vinegar is not allowed to moisten directly the cover with the 
platinised carbon. After five weeks’ work, the platinised carbon is calcined 
afresh. The action of this carbon is very remarkable, the acetification is 
effected more rapidly and completely than in operating in the ordinary way, 
and the vinegar possesses a more agreeable flavour. — Vide Chemical News, 
June 19. 
A hlach aniline Varnish, which promises to be of some commercial value, 
is now being produced in France. The following is the mode of prepara- 
tion : — In a litre of alcohol 12 grammes of aniline blue, 3 grammes of 
fuchsine, and 8 grammes of naphthaline yellow are dissolved. The whole 
is dissolved by agitation in less than twelve hours. One application renders 
a white object ebony black; the varnish can be filtered, and will never 
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