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. 0. 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 Levy and Lacroix's 

 " Mineraux 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 1 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 



