ile, as regards time and trouble, the advantage
lies on the side of the new method. I have completed a determination in
less than two hours from the start, and did not hurry myself over it in
any degree.

Fine pulverization of the sample is not essential, and in fact is rather
detrimental, as the graphite, when fine, is more difficult to wash
without loss. When operating on a coarse sample more time is necessarily
taken, but the resulting graphite shows the manner of occurrence better,
whether in scales or in the amorphous form.

In consulting the literature bearing on the subject, I cannot find any
mention of this method employed as an analytical process; it has,
however, been previously described as a commercial method for the
purification of graphite,[1] and I understand has been tried on a small
scale in this country. The method, though inexpensive, yet seems to have
been abandoned for some reason, and I am not aware that it is now
employed anywhere.--_Sch. Mines Quarterly._

[Footnote 1: Schloffel, Zeitschrift der K.K. geolog. Reichanstalt, 1866,
p. 126.]

* * * * *

SULPHOCYANIDE OF POTASSIUM.

The elements of cyanogen, combined with sulphur, form a salt radical,
sulphocyanogen, C_{2}NS_{2}, which is expressed by the symbol Csy. The
sulphocyanide of potassium, KCsy, is prepared by fusing ferrocyanide of
potassium, deprived of its water of crystallization, intimately mixed
with half its weight of sulphur and 17 parts of carbonate of potassa. The
molten mass, after having cooled, is exhausted with water, the solution
evaporated to dryness, and extracted with alcohol, from which the
crystals of the salt are separated by evaporation.

It is also made by melting the ferrocyanide of potassium with sulphide of
potassium. It is a white, crystallizable salt of a taste resembling that
of niter, soluble in water and alcohol, and extremely poisonous. It
dissolves the chlorides, iodides, and bromides of silver, is, therefore,
a fixing agent, but has not come in general use as such. Vogel speaks
highly of it as an addition to the positive toning bath, although he
prefers the analogous ammonium salt in the following formula:

Chloride of gold solution.... (1:50) 3 c. cm. (46-1/5 grains).
Sulphocyanide of ammonium ... 20 grammes (308 grains).
Water........100 c. cm. (3 ounces 5 drachms 40 grains).

_Ferrocyanide of Potassium_--K_{2}Cfy+3HO, or K_{2}C_{8}N_{3}Fe+3HO, is
generally k