57 
Schimmel & Co. point out that in the Ph. Ndl. IY, the data with 
regard to solubility and specific gravity are given for a temperature 
of 15° C. and in the latter case are compared with water at +4° C. 
They have convinced themselves, by comparative estimations, that 
the differences between specific gravities as compared with water at 
-(-15° and at +4° are so slight that for practical purposes they can 
be neglected, and the specific gravities given in the pharmacopoeia 
can therefore be taken as if based upon that of water at -j— 15°. — 
Semi-Ann. Rep., 1906, -Oct. -Nov., p. 85. 
5. PHYSICAL CONSTANTS. 
Wiebelitz, H., points out that in addition to detailed directions for 
the determination of the melting point it would also be desirable 
to have, in the Ph. Germ., a detailed method for determining the boil- 
ing point and the congealing point of substances. — Pharm. Ztg., Berl., 
1906, v. 51, p. 1003. 
Herissey, H., points out that the manner of determining the points 
of fusion, solidification, and boiling are specified in the Dutch Phar- 
macopoeia. — J. de pharm. et de chim. Par., 1906, v. 23, p. 479. 
An unsigned critique of the Ph. Ndl. IV notes that great care has 
been taken in the determination of solubilities, melting points, and 
boiling points. — Chem. & Drug., Loud., 1906, v. 69, p. 828. 
6. SOLUBILITIES. 
Dott, D. B., asserts that many of the official solubilities require 
revision from a dispenser’s point of view. They should represent the 
amount of substance that can be dissolved by shaking up the sub- 
stance, in a finely divided state, with the solvent at 60° to 65° F. for 
a reasonable length of time. Other methods which may be correct 
in themselves are unsatisfactory from a practical aspect of the ques- 
tion. — Brit. & Col. Drug., Lonch, 1906, v. 49, p. 277. 
An abstract from a paper by O. A. Witt discusses some of the prob- 
lems involved in chemical solubility and points out the need for 
elaborating on the unaided perception of sense by logical reason- 
ing. — Nat. Druggist, St. Louis, 1906, v. 36, pp. 25-26. 
Trevor, J. E., discusses solubility curves and the several factors 
controlling the solubility of various materials. (From J. Physiol. 
Chem., v. 10.) — Chem. Centralbl., Berl., 1906, v. 77, p. 1688. 
Wulff, C., points out that the several pharmacopoeias differ to some 
extent in the methods adopted for indicating the solubility of sub- 
stances; Ph. Austr. and Ph. Ndl. use the designation 1=20, indicat- 
ing that 1 part of the substance is dissolved in 19 parts of the solvent. 
The U. S. P. says 1 in 20, the Ph. Svec. 1+19, and the Ph. Ital. 
1 : 19. — Ber. d. pharm. Gesellsch., Berl., 1906, v. 16, p 155. 
