614 SCIENCE. [N.S. Von. X. No. 252. 
C HON Cl Br I FS P Al As... Zr. C,H;NO, (nitro-benzene); by following the order 
Oo given above this should be C;H;,O,N. For the 
N sake of classification this is a great convenience 
Cl and should be insisted upon in the American 
ay and English journals, for the immense amount. 
r of new material annually added to our already 
R gross number of organic compounds must have 
P systematic arrangement for many obvious rea- 
Al sons. Itis by no means desirable, however, that 
As this take the place of the rational formulas, but. 
be given in addition. To economize space, struc- 
tural formulas are omitted from the volume, but 
- some ten pages are given to the graphic illus- 
LT. 
The arrangement is really automatic, but 
there are some explanations given in the Intro- 
duction by which an empirical formula may be 
deduced from the Index of names which ac- 
companies the tables. The lexicon isa collect- 
ive index to Beilstein for all the compounds 
therein treated, reference to volume and page 
being given. Some 8,000 more are also given. 
These compounds will probably be treated in 
supplements to Beilstein. Polymeric compounds 
with fixed molecular weights are registered 
under their own formulas; (CHON),, cyanuric 
acid is found under C,;H;0;N,. Reference to 
purely theoretical papers are omitted, as well 
as those dealing with analytical, physical, 
mathematical, crystallographic and medico- 
physiological data. Papers which describe 
methods of preparation and properties of the 
substances and the immediate changes they 
undergo only are referred to. ‘The immense 
amount of material has, of course, neces- 
sarily been much condensed, authors’ names 
being omitted and abbreviations of journals 
used. Further, words of frequent occurrence 
have been abbreviated by using the German ab- 
breviations. This is all explained, however, by 
a table giving the meanings of the abridgments 
in the four languages named above. 
The author not only recommends that writers 
in future give the empirical formulas, but also 
adopt the arrangement of formulas as given in 
his book. This attempt at uniformity in the 
writing of formulas has already been inaugu- 
rated by the German Chemical Society in the 
Berichte beginning with 1898. An _ illustra- 
tive example may be given; we usually write 
tration and naming of the ring-systems contain- 
ing O, S, Se, N, P: 
In order to secure a satisfactory nomenclature 
the ‘ principle of substitution’ was adopted. 
For example : 
‘€(1) Every compound with fixed constitution 
is referred to the group-substance from which it 
is derived, namely, to the hydrocarbon or to the 
corresponding cyclic system which contains the 
smallest number of hydrogen atoms, as benzene, 
naphthalene, pyrrol, etc. 
‘¢(2) This group-substance remains intact in 
naming the derivatives and must always figure 
as such in the names of the derivatives, no alter- 
ations taking place, as pyrazole into pyrazoline, 
etc. 
‘¢(3) Hydrogenized group-substances are 
named di-, tetra-, etc., hydroderivatives, as. 
dihydropyrazole for pyrazoline. 
‘‘(4) Group-substances are named, (a) hydro- 
carbons of aliphatic series in accordance with 
the resolutions of the Geneva convention; (6) 
for Aromatic hydrocarbons present used terms 
as benzene, indene, naphthalene, anthracene ; 
(c) Ring systems containing O, S, Se, N, P as 
named in the ten pages adverted. 
‘(5) As the formation of the derivatives of 
group-substances may be regarded as taking 
place by the substitution of hydrogen by other 
atoms or groups, so are the names derived from 
the group-substances. 
Exception, and wisely, is taken to the Geneva 
nomenclature convention in indicating the posi- 
tion of the substituent in the open-chain series 
by letters from the Greek alphabet. In ring- 
compounds, as is usual, the location is indicated 
by numbers. The matter is up-to-date. 
