62 
Arny, H. V., thinks much space might have been saved by giving 
in the appendix the details for the detection of heavy metals and of 
arsenic, as well as of the most important impurities, thus requiring 
under each chemical discussed bare mention of the impurities likely 
to be present, and reference to the article where the test is discussed 
in detail. — Ibid., v. T8, p. 14. 
Herissy, H., in a discussion of the analytical processes of the Ph. 
Xdl. IV. remarks that the description of a process of analysis should 
be so precise as not to leave the initiative to the experimenter; it 
should guide him to the very last weighing, the very last volumetric 
titration. — J. de pharm. et de chim. Par., 1906, v. 23, p. 483. 
u Derlin *' points out that it would be desirable to add to the tests 
for purity in the Ph. Germ, a statement as to what is expected to be 
attained and the degree of purity that must be evidenced. Many of 
the directions, he believes, might be included in the preface or omitted 
entirely and simplv referred to as being according to some other well- 
established authoritative work. Thus, for instance, the determina- 
tion of the iodine or the saponification number could be directed to 
be made according to some previously stated or well-established 
method.— Pharm. Ztg. Berl., 1906, v. 51, p. 993. 
The Pharmacopoeia of Japan directs that the qualitative tests, un- 
less otherwise stated, are done by taking 10 c. c. of its solution in a test 
tube which has an internal diameter of 1.5 cm. In cases where the 
name of the solvent is not mentioned, it being only stated “ a solu- 
tion,’* it is always means that water is used as the solvent. — Ph. 
Japon. Ill, p. XXII. 
The term “ unweighable residue ” is defined by the Ph. Xdl. as being 
less than 1 mg. 
15. CHEMICAL CONSTANTS. 
The Ph. Belg. Ill includes definitions for and suggests methods 
for determining ether index, acid index, iodine index, and saponifi- 
cation index. 
Wiebelitz. H., believes that it would be desirable to include general 
- directions for determining such factors as the iodine and saponifica- 
tion numbers of fats in the preface so as to avoid unnecessary repeti- 
tion. The determination of the ash content should also be outlined 
and the term ” unweighable residue “ should be defined. — Pharm. 
Ztg. Berl., 1906, v. 50, p. 1003. 
Fanto, Bichard, discusses the importance of determining the acid 
number of a varietv of commercial articles, defines what is under- 
stood by the acid number of various substances, and discusses the 
method of determining this factor. — Ztschr. f. ang. Chem. Berl., 1906, 
v. 19, part 2, pp. 1856, 185T. 
i 
