320 
MISCELLANY. 
part in weight of concentrated solution of caustic potash is added to a 
boiling concentrated solution of sulphuret of barium, when the hydrate 
separates on cooling in crystals, which may be purified by recrystal- 
lization. Hydrate of baryta may be obtained quicker, but less pure, 
by decomposing a solution of sulphuret of barium with oxide of cop- 
per; the ley generally contains a slight trace of copper. 
A very simple and cheap method consists in heating a concentrated 
solution of sulphuret of barium w r ith a sufficient quantity of peroxide 
of manganese, until reagents indicate no sulphuretted hydrogen in the 
liquid, and then filtering as quickly as possible. On the cooling of 
the hot concentrated solution, the hydrate of baryta separates in colour- 
less, transparent, four-sided, and flattened six-sided columns, with four 
terminal surfaces, and the filtered ley may be used as barytic water. 
The author could not observe the formation of any hyposulphite of ba- 
ryta. On adding a few drops of basic acetate of lead to the solution 
of sulphuret of barium, which had been heated with sufficient per- 
oxide of manganese, a beautiful brick-red precipitate was formed, 
which however was not examined, and in subsequent experiments 
could not be again obtained. — Ibid, from Jahrb.filr Prakt. Chem. 
Purification of Hippuric Acid. By Dr. A. Bensch. — The fresh urine 
of the horse, that passed in the morning being best, is evaporated in a 
water-bath to one-eighth of its volume, precipitated when cold with 
muriatic acid, the hippuric acid collected on a strainer, strongly 
pressed, and treated with 10 times its weight of boiling water and ex- 
cess of milk of lime. The mixture is strained, pressed, and the fluid 
treated with solution of alum until the alkaline reaction has disap- 
peared: it is then allowed to cool to 104° F., and solution of bicarbo- 
nate of soda added as long as a precipitate ensues, strained and 
pressed, and the clear fluid precipitated with muriatic acid. The 
precipitated hippuric acid, after having been washed and pressed, is 
dissolved in boiling water, an ounce of animal charcoal added to each 
pound of moist hippuric acid, the boiling liquid filtered through paper, 
and perfectly wdiite hippuric acid is thus obtained. The precipitates 
produced are readily separable from the liquid by a linen cloth, not 
passing through the latter when pressed ; hence the purification may 
be accomplished in a few hours, provided the temperature, when the 
bicarbonate of soda is added, does not exceed 104° F. — Ibid, from Lie- 
big's Annalen. 
