February io, 191 6] 



NATURE 



M7 



text-book on physical chemistry dealing with the 

 same subject. There is a slip in the equation of 

 the dissociation constant in Ostvvald's "Dilution 

 Law " on p. i86. 



Henderson's work on the maintenance of^ 

 neutrality in the organism is very clearly de- 

 scribed. In the carbonate phosphate equations 

 given on p. 199 the proportion dissociated of 

 XA0HPO4 in decimolar concentration is given as 

 •004 instead of o"64, as is evident trom the pro- 

 portions required to obtain a hydrion concentration 

 of I •10-'^. There are other slight numerical 

 ■errata in this summary of Henderson's work. 



We can only allude briefly to the remaining 

 ■chapters, which are of a more purely physiological 

 type. The essential characteristic of all is the 

 originality of the treatment. Recent work in pro- 

 tein and carbohydrate metabolism receives due 

 attention, but, as one would expect, the later 

 chapters on catalysis and enzymes and on secre- 

 tion receive much more elaborate treatment. The 

 author very rightly directs attention to the neces- 

 sity for very careful examination of all cases of 

 supposed anti-ferment production. Undoubtedly 

 in many cases the influence of alterations in 

 hydrion concentration and adsorption have not 

 been sufficiently considered in experiments on the 

 production of antibodies. 



The section dealing with excitation and inhibi- 

 tion will l3e read with the greatest interest and 

 profit by all physiologists. 



A slight alteration in the order of the closing 

 chapters might have been advisable. The section 

 on electrical changes in tissues receives an essen- 

 tially modern treatment. It is somewhat pathetic 

 that the older work in this, as in other depart- 

 ments of physiology, has been entirely displaced. 

 There is no reference to the work of Du Bois- 

 Reymond, just as in the subject of reflexes we 

 find no reference to Pfluger's work. In the scope 

 of this brief review we can refer only to the ex- 

 cellent articles on the action of light, on respira- 

 tion, and on the action of hormones, drugs, and 

 toxins. 



The work as a whole requires careful study, 

 and will undoubtedly serve as an incentive to re- 

 search in many departments of physiology. It 

 Is written in a very pleasant style, and its value 

 Is enhanced by the interesting portraits of men of 

 science whose work has contributed to the ad- 

 vance of physiology along the lines dealt with in 

 this work. English physiology is indeed for- 

 tunate in numbering among its most able research 

 workers one who has been able to enrich the 

 science by this most valuable contribution to 

 general physiologv. 



T. H. M. 

 NO. 2415, VOL. 96] 



A HANDBOOK FOR WIRELESS 

 TELEGRAPHISTS. 

 Handbook of Technical Instruction for Wireless 

 Telegraphists. By J. C. Hawkhead. Second 

 edition, revised and enlarged. By H. M. 

 Dowsett. Pp. xvi + 310. (London: The Wire- 

 less Press, Ltd., 191 5.) Price 35. 6d. net. 

 THIS " Handbook of Technical Instruction for 

 Wireless Telegraphists " would more suit- 

 ably be entitled a " Handbook for the use of 

 Marconi Operators in Wireless Telegraphy," be- 

 cause it deals almost exclusively with the methods 

 and apparatus of the Marconi Company. It is 

 divided into three parts : the first concerned with 

 the elementary facts of electricity, the second 

 comprising a couple of chapters on electromag- 

 netic waves and receiving sets, and the third ex- 

 plaining the special appliances and systems of 

 apparatus in use in the Marconi Company's 

 installations. 



Except for the fact that operators on board 

 ship have not generally space in their cabins for 

 many books, it is difficult to see why so much 

 of this book should be occupied with the element- 

 ary information on electrical facts given in dozens 

 of other manuals. In the first chapter the authors 

 suggest that the term "difi"erence of potential" 

 is identical in meaning with the term "electro- 

 motive force." But this is not the case. We can 

 have electromotive force created under conditions 

 in which the term difference of potential has no 

 meaning. Apart from one or two little defects 

 in exposition, the information in part i. is useful 

 so far as it goes, but would scarcely be sufficient 

 for instruction taken alone, and would be un- 

 necessary for operators who have already obtained 

 a grounding in the elements of electrical know- 

 ledge elsewhere. 



Part iii., which deals with the special appa- 

 ratus of the Marconi Company, is, on the other 

 hand, very useful, and is characterised by many 

 excellent diagrams and photo illustrations of 

 actual apparatus. The schemes of connection and 

 internal arrangements of apparatus are particu- 

 larly good and valuable, since the operator out 

 of reach of land is thrown entirely on his own 

 resources if anything goes wrong with his ap- 

 paratus. The great experience of Marconi's 

 Wireless Telegraph Company in land and ship 

 installations has enabled them to perfect, in a 

 very high degree, the details of all their apparatus 

 so as to render it, so far as possible, absolutely 

 certain in operation and highly efficient. 



A very interesting chapter is that on the Mar- 

 coni standard i^-kilowatt wireless telegraph set, 

 which is that mostly used on board ship, every 

 detail of which has been the subject of the most 



