260 



SCIENCE 



[Vol. V., No. 112. 



remembered by the cells, i.e., hallucinations. 

 So, too, an abnormal lack of blood may ex- 

 haust the brain, may render a person incapable 

 of carrying on mental processes, and ma}' even 

 cause such a degree of hunger for oxygen in 

 the cells as in turn to produce irritation, and 

 thus again hallucinations, followed by loss of 

 memory. It is evident that Meynert regards 

 many forms of mental disease as dependent 

 upon abnormal nutrition of the brain, either 

 from hyperaemia or anaemia, — a position in 

 which he by no means stands alone. 



The description of physiological processes 

 in the brain forms a fitting introduction to the 

 study of its disorders. This division of the 

 subject is to be taken up in the second volume, 

 which will be eagerly looked for by those who 

 have read the first. It will doubtless be as 

 suggestive and original as this volume. 



Meynert's book should be read both by 

 medical men and those interested in the prob- 

 lems of psychology. Its technical parts will 

 be of great service to those who study the 

 minute anatomy of the brain. Its physiological 

 portion is of general interest, and will excite 

 much notice and comment. The facts and 

 the conclusions are entitled to careful con- 

 sideration, as they are the product of most 

 mature and thorough work, even though the 

 materialistic explanation is at times inade- 

 quate. Meynert is not to be placed in the 

 ranks of German philosophers. He does not 

 grapple with the problems of psychology, as 

 Lotze or Wiindt have done : he writes from the 

 stand-point of an alienist who seeks to resolve 

 a mental process into its simplest elements, 

 and to detect in an} 7 given case of mental dis- 

 order the particular element which is lacking. 

 The explanation of the manner in which we 

 acquire the idea of space is unsatisfactory 

 (p. 166). The causal relation is not sharply 

 differentiated from the simple association of 

 ideas by correlation in time (p. 164). The 

 time element in memory is not exhaustively 

 discussed. There are, doubtless, many trains 

 of thought which are largely the simple rising 

 into consciousness of associated memory pic- 

 tures. There are others which are not to 

 be so easily accounted for, and to which no 

 clew can be gained by a stud} 7 of association 

 fibres and of variations in the blood-supply. 

 To the psychologist, therefore, this work will 

 be of service only as a collection of facts in one 

 department bearing upon his science, — facts 

 which he must consider, but which by no 

 means carry with them the explanation of the 

 problems involved. 



The work raises many questions which the 



author does not attempt to answer. It would 

 perhaps be unjust to demand from him the 

 attempt, for he does not pretend to be writing 

 as a psychologist. As a study of thought- 

 mechanism, and as an introduction to a study 

 of psychiatry, to which alone it lays claims, it 

 is more satisfactory than any work which has 

 recently appeared. 



ENGINEERING GEOLOGY. 



It is now generally admitted by mining and 

 civil engineers that a knowledge of the princi- 

 ples of practical geology is necessary for the 

 successful execution of those plans, depending 

 upon a correct conception and understanding 

 of the character of the surface of the earth 

 and underlying rocks, where engineering works, 

 such as bridges, railroads, canals, and even 

 buildings, are to be constructed, and through 

 which, as in the case of railroad-tunnels and 

 mines, excavations are to be made. 



The rapid progress which has been made in 

 America during the past fifteen years in prac- 

 tical geology has so completely absorbed the 

 active professionalist, that none of our field- 

 geologists have found time to contribute a 

 treatise to our literature such as Geikie's 

 Field, Penning's Engineering, and Page's 

 Economic geology, Burat's ' Geologie applique,' 

 and the more recent work by Wagner, on ' The 

 relation of geology to the engineering sciences.' 



This last work is an elaborate and strictly 

 technical discussion of the application of prac- 

 tical geology to tunnel-work and closely relat- 

 ed subjects. It contains superior plate (quarto 

 photolithographs) and text illustrations, and 

 will prove a work of great value, not only to 

 professional field-geologists, but to students 

 in practical geology and engineering, in defin- 

 ing some of the more useful and economically 

 important applications of geology to engineer- 

 ing work. 



Some of the geological cross-sections in the 

 text clearly illustrate the geotectonic principles 

 referred to, but evidently perpetuate an abom- 

 inable custom, long since abandoned by the 

 best American geologists, of exaggerating the 

 vertical scale. The chapter on explorations 

 by boring is not up to the standard of our 

 home practice. 



The practical examples cited from Wagner's 

 own experience add much value and interest 

 to the work, which would be more useful to 



Die beziehungen der geologie zu den ingenieur-wissenschaften . 

 Von C. J. Wagner, ober-ingenieur und sectionsleiter des Arl- 

 berg-tunnels. Wien, Spielhagen & Schurich, 1884. 88 p., 65 

 figs., 24 pi. 4°. 



