204 
CHLORIDE OF ZINC WITH GUTTA PERCHA. A NEW 
ESCHAROTIC. 
M. Sommie, in the Bulletin de Therapeutique for June, re¬ 
commends chloride of zinc in cylinders as an escharotic, to 
be prepared in the following manner: 
Gutta percha is first softened with boiling alcohol, and 
then incorporated in a warm porcelain mortar with an equal 
portion of chloride of zinc in a fine state of division. The 
mass is then rapidly rolled out on a porphyry slab, in the 
manner of making pastilles. The cylinders should be made 
of the size of a quill, and divided into portions of several 
lengths, and kept in wide-mouthed bottles with a little pow¬ 
dered chalk. The advantages of this preparation are, that it 
does not liquefy on exposure to the air, and is much more 
manageable than the chloride of zinc .—Pharmaceutical Journal, 
SOLUBILITY OF STARCH IN COLD WATER. 
Whether or not starch, properly so called, is soluble in 
cold water, seems doubtful, but, at all events, when potato 
starch is triturated for a long time in a pestle and mortar, 
with a small quantity of water, or is rubbed for a shorter 
time with quartzoze sand, and a little water, and then more 
water is added, a solution is obtained which gives an intense 
blue colour with iodine. Before the iodine is added, the 
mixture should be allowed to repose for twenty-four hours, 
and then the clear liquor should be decanted and filtered 
through Swedish paper. The solution so obtained is per¬ 
fectly clear, and the microscope shows no trace of matter in 
a finely-divided state. The starchy matter must therefore be 
perfectly dissolved. The blue colour produced when iodine 
is added disappears when the liquid is heated, and reappears 
on cooling. No deposit of iodide of starch is obtained on 
standing. Basic acetate of lead gives a voluminous white 
precipitate with the solution, just as with solutions of gum; 
the neutral acetate does not. Baryta water gives a white 
precipitate. Fehling’s cupro-potassic solution is reduced in 
the cold. Nitrate of protoxide of mercury, chloride of gold, 
perchloride of iron, and sulphate of copper, do not produce 
any precipitate. Delffs supposes that the matter dissolved 
must have the same composition as starch, C 6 H 5 0 5 , or must 
