404 
PREPARATIONS OP LACTIC ACID. 
Lau i’bmann recommends that oxide of zinc be substituted 
for chalk in the preparation of lactic acid by the fermentation 
of sugar and cheese. The mixture must be kept at the tem¬ 
perature of 40° to 45°, and frequently stirred. The operation 
is completed in about eight or ten days. The mixture is 
then boiled and filtered, and the liquor evaporated, to obtain 
the lactate of zinc. One or two crystallisations will furnish 
this salt sufficiently pure for the preparation of the acid, 
which is done by precipitating the zinc with sulphuretted 
hydrogen. Some mannite is always present, but may be 
separated by concentrating the solution, and extracting the 
lactic acid with ether. The mannite remains in the aqueous 
solution. 
GLYCERINE A SOLVENT FOR ARSENIOUS ACID. 
Arsenious acid appears to be very soluble in glycerine. 
M. Cap states that equal equivalents of the two substances 
combine, yielding a viscous body, which solidifies at the 
freezing point of water, and presents the appearance of or¬ 
dinary fat. 
SOLUTIO ATROPLE GLYCERINEA. 
Under the above name, a solution of atropia, the active 
principle of the deadly nightshade in glycerine, has been re¬ 
commended by Mr. R. C. Tichborne, for dilatation of the 
pupil in cataract, iritis, &c. 
He objects to the use of the extract of belladonna, because 
of its “liability to produce cutaneous irritation; secondly, 
its requiring great attention in keeping the surface moist 
with some lotion to prevent its drying; and thirdly, want of 
cleanliness, as the extraneous manners of the inspissated 
juice are certainly very much out of place when manipulating 
with so delicate an organ as the eye; and in some cases com¬ 
plete failure results either from the use of a bad preparation 
or non-absorption from harshness of the epidermis.” 
Glycerine has been found to possess great solvent pro¬ 
perties, particularly as regards the alkaloids, and some of the 
