May 23, 1912] NATURE 293 
Le >, : a | | a eee 
series,” starting from uranium, thorium, and | show that the author has that wider range of know- 
actinium, are considered, and a note is added in 
reference to the slight radio-activity of potassium 
and rubidium. <A concise statement of the present 
position of radio-chemistry is very opportune, and 
will be welcomed by many readers who are not in 
a position to master the original literature of the 
subject. 
(4) Messrs. Dunstan and Thole have included 
in one volume instructions for qualitative analysis, 
volumetric and gravimetric analysis, gasometry, 
organic analysis and identification, and physico- 
chemical determinations; tables of solubility, re- 
agents, atomic weights, logarithms, melting- 
points and boiling-points are given as appendices. 
Qualitative analysis is dealt with largely from the 
ionic point of view, but exception must be taken to 
the suggestion on p. 12 that H. C. Jones is the 
originator of the view that the ion is ‘‘ associated 
with a variable amount of solvent”; this author’s 
first statement was that the molecules of a salt, 
and not the ions, are hydrated, and this erroneous 
view was not withdrawn until the idea of hydrated 
ions had become generally familiar from the work 
of Kohlrausch and others. The book does not 
contain any detailed series of organic preparations, 
though general instructions are given for acetyla- 
tion, nitration, preparation of oximes, &c. ; but the 
chapter on organic identification is unusually com- 
plete, and forms one of the most valuable features 
of the book. 
(5) Dr. Cumming has compiled a very attractive 
practical chemistry for medical students, lead- 
ing up from exercises on solubility, &c., to the 
examination of organic compounds. The earlier 
exercises appear to be almost too simple, and it 
may be doubted whether the separation of salt 
from sand and the recrystallation of potassium 
nitrate mixed with a little permanganate are 
actually carried out by the medical students in the 
Edinburgh laboratories. Ina later edition it would 
be well to accord to “bunsen” the dignity of a 
capital letter. 
(6) Mr. Weston’s book is intended for the use 
of beginners, and deals with solution, air, water, 
acids, alkalis, salts, the common gases, and the 
laws of chemical combination. A feature of the 
work is the photographic reproduction of actual 
apparatus; the reproductions are usually good, 
but a badly-bored cork which makes its first ap- 
pearance in Fig. 20 shows itself again in the later 
pictures with the frequency attributed to the “bad 
penny”; the face reproduced in Fig. 50 would 
give the impression that a pipette is a worrying 
instrument to use. The success of a practical 
course depends almost entirely upon the teacher in 
charge of the laboratory, and the incidental notes 
NO. 2221, VOL. 89] 
ledge which contributes so much to the interest of 
the work. Black’s work on “fixed air,’ referred 
to on p. 83, should be dated 1755 and not 1775. 
(7) Historical notes are a feature of the 
“Chemistry Note-book,” whereby Mr. Sumner 
seeks to supplement the imperfections of a school- 
boy’s “notes.”” The book is published locally, 
and is issued in a form which does not lend itself 
to any modification of the course which the author 
has adopted in his own school; but the course is 
a good one, and it may be that other teachers will 
be content to follow it so closely as to render 
possible the use of the printed ‘‘note-book.” 
Incidental faults are the occasional use of formule 
as abbreviations, a bad habit that needs no en- 
couragement from the teacher of a class of boys, 
and the slovenly use of the adjective (? ) ‘‘bunsen.” 
The eleven pages of historical outline at the end of 
the book are of more general value, and go far to 
guarantee the qualifications of the author to devise 
a successful course of elementary chemistry. The 
list of elements “discovered”? by Berzelius is a 
curious one: there seems to be some confusion 
between the discovery and the isolation of an 
element, and it would be easy to dispute the claims 
of Berzelius to one or other of the two stages in 
the ‘‘discovery ” of barium or silicon. 
(8) Dr. Spencer has provided a course of experi- 
| mental work to run side by side with a lecture- 
course in physical chemistry; the first part, deal- 
ing with “statical experiments,” is now issued as 
a separate volume, to be followed by a volume 
describing the more difficult dynamical experi- 
ments. The methods of measuring the mechanical, 
optical, and thermal properties of substances are 
illustrated in an ample series of experiments. 
The methods to be used in correcting a balance 
and calibrating the weights are described, together 
with the correction to vacuum standard. It is to 
be regretted that the correction for latitude is 
deliberately excluded, and that the vacuum correc- 
tion is not used systematically in the later experi- 
ments. It is not generally realised by chemists 
that a boiling point under a given pressure of 
mercury has no accurate significance until a cor- 
rection has been made for latitude, for height 
above sea-level, and for the temperature of the 
mercury of the barometer; the systematic neglect 
of such corrections is a source of much inaccuracy, 
and it should be one of the chief objects of a 
_ course of experimental work in physical chemistry 
publishing uncorrected observations. 
to get rid of the slovenly habit of making and 
In a later 
edition the author will perhaps use his opportunity 
‘ to develop this important feature in a book that is 
likely to be widely read and used. 
