OcToBER 13, 1899.] . SCIENCE. 533 
type to justify fully the expenditure. Unfor- errors will be found in the text and in the 
tunately it is disfigured by a great number of 
typographical errors, for most of which the 
authors are, clearly, not responsible. A reform 
in public printing offices is necessary, for, in 
too many cases, reports are a source of annoy- 
ance and confusion of face to those who prepare 
them. 
JOHN J. STEVENSON. 
Les matiéres colorantes azoiques. GkroRGES F. 
JAUBERT. Docteur és Sciences, ancien 
Préparateur de Chimie 4 VEcole Polytech- 
nique. Petit in-8. (Encyclopédie scientifique 
des aide-mémoire.) 
This little book appears as one of the vol- 
umes in the ‘Encyclopédie scientifique des 
aide-mémoire,’ now being published in Paris 
under the direction of M. Léauté, Member of 
the Institute. It is asequel to a previous vol- 
ume in the collection, and by the same author, 
entitled ‘L’Industrie du goudron de houille.’ 
The subject matter is divided into the following 
chapters: 1. Nitro colors; 2. Azoxy colors; 3- 
Azo derivatives ; 4. Aminoazo colors ; 5. Oxyazo 
colors; 6. Azo colors dyeing upon mordants ; 7. 
Polyazo colors derived from monamines; 8. 
Polyazo colors derived from diamines. The chap- 
ters on the Nitro and Azoxy colors are inserted as 
introductory to the Azo colors. The few pages 
of text present are devoted toa brief statement 
of the most important general properties of the 
Nitro, Azoxy, and Azo dyes; while the body 
of the work is made up of a tabular classifi- 
cation of the more prominent Azo colors, under 
the following column headings: Scientific and 
trade name; method of preparation ; chemical 
formula, empiric and constitutional ; literature, 
patents, ete., properties, reactions, etc., indus- 
trial application. It will thus be seen that the 
classification is practically the same as that 
made familiar to all color chemists by the tables 
of Schultz and Julius, and also used by Hehne, 
Green, Seyewetz and Sisley, and others. The 
book is, however, of a much more convenient 
size than the work of Schultz and Julius, al- 
though its scope is more limited. The newer 
Tetrazo colors, which have played such a promi- 
nent part in the substantive dyeing of cotton, 
are very fully listed. Several typographical 
constitututional formulas. 
Dealing, as it does, with the most numerous 
and the most important group of all artificial 
dyestuffs, the Azo Colors, this succint classifi- 
cation should prove most useful both to the 
student and to the manufacturer. 
M. T. B. 
A Century of Vaccination and What it Teaches. 
By W.Scorr Tess. London, Swan, Sonner- 
schein & Co. 1899. Second Kdition. 
In this book of 403 pages, Dr. Tebb presents 
at considerable length the usual anti-vaccina- 
tion arguments, directing them by English ex- 
amples especially to an English audience, and 
attacks the compulsory vaccination common in 
England before the law of 1898. Much of the 
space in the book is taken up with settled ques- 
tions or matters not directly concerned in the 
point at issue; for example thirty pages dis- 
cuss admittedly inconclusive experiments per- 
formed about 1800, thirty are spent on the un- 
sanitary conditions of England in the last 
century, and of any place in war time, and 
twenty-six more give examples of small-pox oc- 
curring after vaccination and revaccination. 
Dr. Tebb’s reasoning is three-fold : First, that 
an attack of cow-pox does not secure immunity 
against small-pox because the latter disease 
sometimes follows the former; second, that 
serious injuries are produced by vaccination, 
and third that even if immunity could be gained 
by vaccination, compulsion would be unjusti- 
fiable. Immunity from any disease is a clinical 
fact not yet by any means fully understood > 
and it is well known both that, some persons 
variously estimated at from 1 to 2 per cent. are 
naturally immune to small-pox, just as there 
are some immune to almost every other infec- 
tious disease, and that small-pox sometimes oc- 
curs and even proves fatal after both vaccina- 
tion and revaccination and after a previous 
attack of small-pox. All now claimed is that 
successful vaccination confers against small-pox 
an almost absolute immunity for six months, 
and then further for an unknown and variable 
length of time a certain degree of immunity 
which is greater than can be gained in any 
other way except, by taking the disease. The 
