JULY 1899] THE SENSE OF HEARING 63 
more especially for the cochlear division, the view is strengthened that this is 
the part of the nerve really connected with hearing, while the vestibular portion 
has to do with the transmission of the result of pressures connected with the 
sense of equilibrium and the position of the head (and perhaps the body) in 
space. True auditory impressions not only pass to their appropriate centres in 
the cerebrum but they may arouse, in a reflex way, many motor mechanisms, 
by their transmissions to the deep origins of probably all the motor cranial 
nerves. This striking fact suggests an explanation of how it is that music 
penetrates into the very roots of our being, and thrills us through and through. 
At the close of the book, there is an interesting chapter on the results of 
pathological inquiries into the condition of the internal ear in deafness, and in 
cases of deaf-mutism. These results all support Helmholtz’ theory of the 
analytic action of the cochlea. The real difficulties in the way of the full 
acceptance of this theory, namely, the perception of noise and the nature and 
influence of combinational tones, are not discussed. 
The value of the book is lessened by the want of a good index. Altogether 
this is an excellent work, of a semi-popular character adapted for the perusal 
of any one who desires to know something of a fascinating subject, without 
having to plunge into mathematico-physical investigations. The latter, however, 
along with adequate anatomical knowledge, are the only means by which an 
accurate knowledge of the wonderful sense of hearing can be obtained. 
JoHN G. M‘KENDRICK. 
SCIENCE AND QUARRYING. 
Steinbruchindustrie und Steinbruchgeologie. By Dr. O. HERRMANN. 8vo, 
pp. Xvi. +428, with 6 plates, and 17 figures in the text. Berlin: 
Gebriider Borntraeger, 1899. Price 10 marks. 
This excellently printed work is, as its author is careful to point out, largely 
devoted to the stone industries of Saxony; but a general review of useful 
stones is also undertaken. The list of books helpful to the reader would 
astound a quarry-owner, but shows how the author is intent on putting forward 
mineralogical and geological knowledge as the true basis for the practical treat- 
ment of rock-masses. We miss, however, from this list Lévy and Lacroix’s 
**Minéraux des roches,” and the admirable tables of the same authors. While 
England is well represented, only three French works seem quoted, which is a 
loss when one considers the present brilliant position of geology and mineralogy 
throughout France. 
The work opens with a modestly-written description of the common rock- 
forming minerals, stress being laid on the characters that make their presence 
welcome or unwelcome in building materials. An account of rocks then follows, 
based on Zirkel’s text-book ; but it seems unwise to introduce the question of 
geological-age at this late period into the classification of the igneous masses. 
What would a German quarryman think, were he imported into the Mourne 
Mountains or the Pyrenees? It is a pity, at any rate, to give grounds for the 
suspicion that geology is a matter of names, and of no value to the ‘practical 
tradesman.” Pp. 83-150, however, should go far to show how minute structural 
details, or conditions of original deposition, such as those studied by the geolo- 
gist, fundamentally affect the utility of rocks when they come to be placed upon 
the market. We gather from p. 180 that the growth of the artificial stone 
industry already affects the business of German quarries, and that the rates 
charged on railways are among the obstacles to progress. The same may be said 
with greater force of our own islands; and it is a question whether artificial 
stones, of uniform excellence, may not in time supersede natural ones for city 
use. This will only be a further example of science applying the tools of nature 
