MANUFACTURE OP BORAX. 
Ill 
acid reaction on moistened litmus-paper, that it is fusible, 
and that it possesses the general characters of a neutral 
fatty substance. — Ibid, from Chimie appliquee aux Arts. 
i 
ART. XXVIII. — ON THE MANUFACTURE OF BORAX. 
By M. Koehnke. 
The author gives the following directions for the carry- 
ing out of his process : 
In the preparation of borax from crude crystallized car- 
bonate of soda and crude Tuscan boracic acid, a solution of 
caustic soda is prepared, amounting to about 170 lbs. of 
1-090 to 1-095 spec, grav., which requires on an average 
50 lbs. of soda and 30 lbs. of good caustic lime, the latter 
mixed to a paste with 4 times its weight of water. When the 
mixture has been boiled in an iron pan, and converted into 
caustic ley, it is carefully covered, and after the lapse of a 
few hours the clear ley drawn off by means of a siphon, the 
residue again treated with a further quantity of water, 
well agitated, and the clear liquid again drawn olf after a 
few hours' rest. A further quantity of water is poured 
over the residue, which is subsequently removed to be em- 
ployed in washing the crystals of borax obtained. 
The leys thus obtained are boiled down to 170 lbs. or to 
1-090 — 1-095 spec, grav., and then 40 lbs. of good Tuscan 
boracic acid introduced, and further boiled until the ley is 
reduced to 120 to 125 lbs., or indicates 1-175 — 1-180 spec, 
grav. ; upon this the liquid is poured boiling hot into a wooden 
tub which is well surrounded with woolen cloths and straw, 
and carefully covered to retain the heat as long as possible, 
so that a good and regular crystallization may be effected. 
When borax crystallizes from a warm solution at from 
