August 2, 19 17] 



NATURE 



44: 



with an experimental stag^e of the subject, which 

 may, however, have considerable possibilities of 

 actual utility in warfare. 



In any future edition of his book the author 

 would be well advised to cut out all unessential 

 matter. He is not a safe g-uide on points of 

 history or priority in relation to radio-telegraphic 

 invention. His statement on p. 32 as to "later 

 improvements " is absurdly inaccurate. On 

 pp. 105 and 106 he misspells the name of Prof. E. 

 Branly, the inventor of the metallic-filings coherer. 

 On p. 173 he gives exclusive credit for the vacuum 

 valve detector to Lee de Forest, apparently in 

 entire ignorance that the Court of .\ppeals in the 

 United States has confirmed Judge Mayer's deci- 

 sion that the de Forest audion is an infringfement 

 of the Fleming oscillation valve. He is also 

 seemingly unaware that the so-called Dolbear 

 system of wireless telegraphy was never operative. 

 In spite of the fact that there is a free use of 

 photographs of apparatus which are insuflficiently 

 described in the text, the reader who is desirous 

 of learning- what can be done in the radio-control 

 of torpedoes will find a good deal of suggestive 

 research described in this little book. J. A. F. 



THE ACTION OF ENZYMES. 



The Method of Enzyme Action. By Dr. J. 



Beatty. With Introduction by Prof. E. H. 



Starling. Pp. ix+ 143. (London: J. and A. 

 Churchill, 1917.) Price 55. 



'pWO-THIRDS of this book is devoted to an 

 -•- excellently clear and concise account of the 

 facts and theories to be found in the books named 

 in the preface, so far as they are connected with 

 the action of enzymes. What is new, and the 

 chief object of the book, is the sug-gestion of a 

 hypothesis of enzyme action. The details can 

 be adequately grasped only from the full descrip- 

 tion. It is based on two assumptions : (i) the 

 possibility of "combination " between molecules, 

 and (2) the loosening of internal bonds in one or 

 both of the combining molecules as a result of 

 this union. It is held that the action of all enzymes 

 can be reduced to the combination with H and 

 OH radicles derived from water. These radicles 

 are "activated" by the power possessed by an 

 enzyme of "attracting " one or the other. This 

 is a general or unspecific property, but each 

 enzyme has also a specific power of adsorbing 

 some particular substrate. The author will, no 

 doubt, admit that considerable further explana- 

 tion is required as to the means by which the 

 activation is effected, and criticism is difficult 

 until more is known of the nature of the atom 

 itself and of the way in which it is united to other 

 atoms. 



The hypothesis deserves to be kept in mind as 

 more knowledge is grained of the action and the 

 nature of enzymes. At present it is not easy to 

 imagine ways of putting it to experimental test. 

 Indeed, it must not be forgotten that the funda- 

 mental assumptions are not universally accepted. 

 jThe present writer is inclined to think that the 

 XO. 2492, VOL. 99] 



use of the word "combination," although very 

 common, in speaking- of the union between mole- 

 cules and even of adsorption, is apt to lead to an 

 obscuring- of the g^reat, salient facts of true chemi- 

 cal union. There are, as it seems, various stages 

 of "combination," leading- from adsorption, 

 through molecular compounds, to cases where the 

 change of properties is of the most striking- kind. 

 It is somewhat unfortunate that the new 

 hypothesis appears to involve the explanation of 

 all catalytic action by the formation of inter- 

 mediate compounds. This has been shown 

 actually to take place in one case alone of 

 heterogeneous catalysis, and since the compounds 

 are only supposed to exist momentarily, it seems 

 somewhat hopeless to exf>ect a proof or disproof 

 of their existence. The p>ossibility of represent- 

 ing a reaction by a chemical equation does not 

 necessarily show that it takes place in that way. 

 The division of catalysts into inorganic and 

 enzymes would be better replaced by that into 

 homogeneous and heterogeneous, the latter to 

 include enzymes. There are more differences 

 between catalysis in homogeneous and heteroge- 

 neous systems than between inorg^anic heteroge- 

 neous catalysts and enzymes. In fact, more 

 knowledge of the mechanism of heterogeneous 

 catalysis is greatly to be desired. In future 

 developments of his hypothesis the author might 

 also find it of advantage to consider it more fully 

 in the lighf of the doctrines of energetics. 



\V. M. B. 



OUR BOOKSHELF. 



Clinical Bacteriology and Haeniatology for 



Practitioners. By Dr. ^^^ D'Este Emery. 



Fifth edition. Pp. xiii + plates xi -f pp. 310. 



(London: H. K. Lewis and Co., Ltd., 1917.) 



Price 95. net. 

 .A NEW edition of Emery's "Clinical Bacteriology 

 and Haematolog^y " is ahvays welcome, for it is 

 a most useful book for the practitioner and 

 for laboratory work. The general plan has been 

 mamtained in this fifth edition, but the text has 

 been revised, some new matter added, and some 

 more illustrations have been inserted. 



In the section dealing with syphilis the 

 Mcintosh and Fildes method of performing^ the 

 Wassermann reaction has been inserted in addi- 

 tion to the author's own method, and we think 

 the author has been well advised to do this. 



The Dreyer method of performing the agglu- 

 tination test for typhoid fever is also described 

 in full as well as earlier methods. 



Cerebrospinal fever and the recognition of the 

 meningococcus are dealt with more fullv than 

 previously, and the examination of carriers is 

 described. Even now this section is none too 

 long, and might be extended with advantage. 

 We doubt if it is wise ever to rely on ordinarv 

 agar as a culture medium for this organism, as 

 is suggested. 



Malaria is described very briefly, and no men- 

 tion is made that the crescents of sub-tertian 

 fever are free in the blood-plasma and are not 



