330 
NATURE 
(Fan. 247, 1870 
that the pupil should strive, not only to Anow, but to 
reason. \t is, indeed, precisely at this point that the 
power and merits both of teacher and writer become most 
apparent; and we have no hesitation in saying that it is 
in this sphere that the efficacious distinction between one 
manual and another lies. 
After “Directions to the Reader” (as to the most 
advantageous mode of using the book), a list is given of 
the chapters into which the subject is divided. An 
exhaustive series of questions follows each chapter. A 
great deal of space has been gained by printing many of 
the necessary comments and descriptions in a smaller 
type than the more important text ; and the illustrations, 
tiough generally of diminutive size, are no doubt large 
eiough, and certainly distinct enough, for most readers. 
It need hardly be said that the province of Chemistry for 
Schools is comprised within the limits of the “ metalloids” 
and their immediate allies. The nomenclature employed 
is throughout what has been termed “ Berzelian,” but is, 
in fact, derived from the hereditary Latin forms, which have 
been common for centuries to the whole of natural 
science, and are still the only ones which can be legiti- 
mately adapted to the requirements of our own language. 
‘The writer terminates with some useful appendices, not 
the least valuable of them being a list of necessary appa- 
ratus and chemicals, with approximate cost. 
Mr. Gill has fairly earned the thanks of scientific 
chemists ; nor will the schools be slow to appreciate a 
manual which has been thus well devised and executed by 
an author who has himself been a successful school 
teacher. 
The Blow-Fly.—A Monograph on the Anatomy and 
Physiology of the Blow-Fly, By Benjamin Thomp- 
son Lowne. (Van Voorst.) 
In this little volume, just issued by Van Voorst, Mr. 
Lowne has treated the subject of his monograph very 
exhaustively. The text is judiciously divided into two 
parts, the first comprising a neat popular sketch of the 
organisation of this familiar and pertinacious little com- 
panion of domestic life ; and the second containing the 
more technical and elaborate account of the author’s own 
dissections and investigations, which are illustrated by ten 
very beautiful plates, engraved by his own hand from his 
own microscopical demonstrations. 
The book is eminently satisfactory, as being a clear and 
complete statement of what is known of fly-organisation. 
But it has also, in some degree, the stamp of original re- 
search upon it, and represents a remarkable amount of 
labour and industry. The nature of the all-embracing 
integuments, and the way in which they are modelled to 
form the external organs and implements of the creature’s 
active life, are in the first instance dwelt upon. The 
theme then passes on to the examination of the digestive 
and assimilative apparatus, the arrangements for circula- 
tion and respiration, the nerve structure, and the organs 
of special sense. It would be possible to pause upon 
matters of particular moment and interest in each 
one of these departments of the treatise. But it 
must, for this occasion, suffice to draw attention to the 
explanation of the way in which the so-called false tracheze 
of the trunk are modelled into an exquisite strainer, to 
enable the fly to draw off the finer and more nutritious 
parts of the half rotten pulpy matters that are used as 
food, and to the manner in which the terminal lip of this 
sucking trunk is furnished with supplementary rasping 
teeth and salivary pores, to allow such matters as loaf 
sugar to be broken down and dissolved into a juice also 
available for suction. The description of the manner in 
which the poisers, properly the abortion of the second 
pair of wings, are turned to account as ears which receive 
the vibrations of sound upon terminal knobs, instead of 
within trumpet cavities, is also most worthy of notice. 
But before all must stand Mr. Lowne’s demonstration of 
| the fiy brain. 
He shows that the fly has a sense-centre, 
or cephalic ganglia, some thirty times larger than that of 
the most portly beetle, which sufficiently accounts for the 
energy and vivacity of the insect’s life ; and that it has also, 
in common with the bee and the ant, a small rudimentary 
convoluted brain, attached by a little footstalk to the 
larger and simpler nerve-mass of the head. Mr. Lowne 
holds that the fly clearly exhibits some trace of mental 
faculty, such as memory, in virtue of this shadowing forth 
of true cerebral organisation. 
Terrestrial Physics.—Ueber die Lehre von den Meeres- 
stromungen. By Dr. Adolf Muhry. (Gottingen, 
1869. London: Williams and Norgate.) 
THIS is a very successful attempt to introduce something 
like order into the complicated phenomena of oceanic 
currents. The author sketches first the two well-known 
main systems, viz. (1) the great west-current which forms 
a belt of nearly 50° of latitude on both sides of the equa- 
tor, and to which the earth’s rotation, combined with the 
inertia of the ocean, is assigned as cause ; (2) the great 
thermal circulation from the poles towards the equator, 
with its compensating current in the opposite direction ; 
both are, according to the author, produced by the differ- 
ence in density of cold and warm water, and he refutes, 
with great knowledge and sagacity, the opinions of pre- 
vious writers, of Maury among others, who seek the cause 
in differences in the amount of evaporation and rain, 
the prevailing winds, and the amount of saline matter in 
the sea. 
Then follows an exposé of comparatively local systems. 
Here the author supplants the incompleteness of known 
facts by his own speculations, which are neither always 
clear nor above the suspicion that doubtful points have 
been decided by the author, with a view of confirming his 
own hypotheses. Thus a very elaborate chapter on the 
currents in the North Polar Basin rests entirely on his 
assumption that sea-water behaves like pure water as 
regards the temperature at which it has the greatest 
density. He describes some very crude experiments made 
by him, which prove the fact in his opinion, but are con- 
tradicted by the well-known experiments of such a distin- 
guished physicist as Despretz, who found different points 
of maximum density for different saline solutions. 
aples 
Protozoe Helvetica. —MWittheilungen aus dem Berner 
Museum der Naturgeschichte tiber merkwirdige 
Thier-und Phlanzenreste der schwetrzerischen Vor- 
welt. Edited by W. A. Ooster and C. von Fischer- 
Ooster. Part I. Basle and Geneva, 1869. 4to. pp. 14, 
map and two double plates. (London: Williams and 
Norgate.) 
THIS is the first fasciculus of a series intended to illustrate 
the palzontology of Switzerland. The work is intended 
chiefly as a means of making known by descriptions and 
drawings a number of interesting fossils from the animal 
and vegetable kingdom, in part at least new to science. 
Most of these have been derived from the Swiss Alps, and 
are now preserved in the Bern Museum of Natural His- 
tory. It is also intended to serve as the organ for shorter 
paleontological communications from the whole extent of 
Swiss territory, the several authors being answerable for 
their own views. The first part contains a short paper, 
just completed, “On the Red Limestone of Wimmis and 
its Fauna ;” the next will contain plates and descriptions 
of various remarkable fossils from the Swiss Alps. 
Three, or at most four such parts will form a volume, 
when a title-page and index will be issued. 
We need onlyadd that the plates before us contain figures 
of fish-teeth (Oxyrrhina, sp.), mollusca (/noceramus Brun- 
ne,z, and an undetermined species), and echinodermata 
(Collyrites Friburgensts and C. capistrata), that the draw- 
ings are of large size, and, except for occasional flatness 
in the shading, well-executed, HBB; 
