ZOOLOGY AND BOTANY, MICllOSCOPY, ETC. 
431 
evidently feels this, and remembering the little time at the disposal of the 
student, has sought to condense and put in the most concise and practical 
form what it is well for him to know about his instrument in theory and 
practice. We cannot say that a student can consider his knowledge as 
either wholly satisfactory, or in any sense exhaustive, when derived 
from this book alone ; but on the points in difficulty ho can readily 
consult more exhaustive treatises. The illustrations are crude, but they 
are only intended to be diagrams, and are in the main made to convey 
the points specially emphasized. 
On mounting there are some good practical hints, and there is a very 
useful bibliography, with an index completing the volume. We con- 
clude that this book has a raison d'etre, and will, especially in America, 
command a good audience. 
Behrens’ Tables for Microscopists.* — The appearance of this second 
edition of Behrens’ useful tables will be welcomed by microscopists. 
The new edition forms really a new work, for few only of the tables of 
the original remain unchanged. In the preparation of this greatly 
enlarged edition, Dr. W. Behrens has had the assistance of several 
eminent authorities. The 76 pages of the first edition have been 
extended to 205, while the number of separate tables has been increased 
from 54 to 76. The arrangement of the tables remains very much the 
same as in the first edition. The most important addition consists in 
two long tables devoted to microchemical reactions, for botanical and 
mineralogical investigations. 
Nature of Solutions and the Use of the Microscope.f— In a dis- 
cussion on solut on and pseudosolution, Mr. H. Jackson remarked that 
he had found in the case of lead hydrate that the Microscope revealed 
moving particles with an average diameter of 1/35,000 in. Some, in 
the case of silver nitroprnsside, were less than 1/100,000 in. It is quite 
clear that it is impossible to call a liquid homogeneous because the 
Microscope fails to show structure. All that can be said is that the 
particles in water, if not visible with lenses of the greatest possible 
angle for water, are probably not much greater than 1/180,000 in. 
in diameter. 
The late Mr. W. W. Reeves. — The Fellows will hear with regret 
of the death of one of the most constant attendants at our meetings, and 
one well known, especially to the older Fellows, in consequence of his 
having been Assistant Secretary to the Society from 1868 to 1883. Ho 
has served on the Council since 1890. Our deceased friend died on the 
18th of May last. 
Duval, A. — Le. technique microscopique et histologique. (Microscopical and 
Histological Technique.) Paris (Bailliere) 1891, 16mo, 43 figs. 
Schiefferdecker, I’., i*. A. Kossel — Gewebelehre mit hesonderer Beriick- 
sichtigung des menschlichen Kdrpers. [Brl. II. von W. Behrens, A. Kossel u. 
P. Schiefferdecker, Die Gewebe des menschlichen Kdrpers und ihre mikroskop- 
ische Untersuchung.] (Histology, with special reference to Man (Vol. II. Ti e 
Tissues of the Human Body, and their examination by the Microscope.) 
1. Abtheil , Braunschweig, 1891, 8vo, 414 pp., 214 figs. 
* Behrens, W., ‘ Tabellenzum Gebrauch bei mikroskopisehen Arbeiten. Zweite 
neu bearbeitete Auflage,’ Braunschweig, 1892, 8vo, 205 pp. 
t Froe. Chcm. Soc. London, No. 104 (1891) pp. 178-9. 
