July 17, 1884] 



NATURE 



263 



and g, without its being so stated, is taken in inches per 

 second per second. 



A chapter headed " Testing of Electric Light Dynamos, 

 Accumulators, and Transmission of Power," given at 

 pp. 176-86, is not at all satisfactory. The tests for 

 the efficiency of a secondary battery are neither clearly 

 nor fully given, and the score of lines devoted to this 

 important subject close with a most remarkable sentence, 

 which we quote : — " The total work done in charging and 

 discharging may also be measured by a suitable voltame- 

 ter joined up as a shunt to the secondary battery, so as to 

 pass a Known fraction of a current through it." 



At p. 373 there are two or three misprinted formulas, 

 but in the first line of p. 374 we have perhaps the most 

 extraordinary equation ever given in a work on electro- 

 dynamics. The difference of potential at the terminals 

 of a dynamo (a shunt-dynamo we presume is meant) is 

 there stated to be equal alternatively to the product of the 

 current in the field magnets multiplied into their resistance, 

 to the current in the external circuit multiplied into the 

 resistance of the external circuit, and to the current in the 

 armature multiplied into the resistance of the armature .' 



The calculation (p. 345) relative to the electrolytic de- 

 composition of copper sulphate involves also serious theo- 

 retical errors. Mr. Jamieson, multiplying together the 

 electro-chemical equivalent of copper and the heat of 

 combination of copper and oxygen, makes the " electro- 

 motive force required to deposit copper from a solution 

 of sulphate of copper" to be '836 volt. In the par- 

 ticular case, not however referred to, of a cell having 

 a platinum anode and copper kathode, this would be the 

 approximate electromotive force required on the cell to 

 produce electrolysis. But the author actually goes on to use 

 this result as the electromotiveforce required on an ordinary 

 electro-plating bath to effect the electrolysis, and bases 

 on it some conclusions as to the efficiency of a Siemens 

 machine depositing copper in commercial work, or in the 

 stereotyping of ordinary printed matter. In these cases 

 of course both anode and kathode are copper plates, and 

 the calculated electromotive force has no application 

 whatever. 



A single remark on another subject we would make 

 before taking leave of this work. In many places where 

 the compilers are under obligations to other authors due 

 acknowledgment is wanting. For examples we may refer 

 to several parts of the chapter on submarine telegraphy, 

 to pp. 369-76 on dynamos and transmission of power, and 

 to part of p. 403, where, by the way, the very serious errors 

 inherent in the method of determining (?) the intensity of 

 a magnetic field by counting the oscillations of a magnetic 

 needle are not alluded to. 



In conclusion we have no hesitation in saying that with 

 a careful weeding of the tables, minute verification and 

 correction of the algebraical work, deletion of a good deal 

 of the " theory " given, and lastly, copious references to 

 original sources, both as a matter of convenience to the 

 user and of literary justice, this " Pocket-Book" will be 

 made a very valuable vade mecum for electrical engineers. 

 As it is, it will no doubt be found of service, but, as we 

 have indicated, its statements must on several subjects 

 be received with caution. A. GRAY 



The Xon-Bacillar Nature of Abrus Poison. By C. J. H. 



Warden, Surgeon I. M.S., and L. A. Waddell, Surgeon 



I. M.S. (Calcutta, 1884.) 

 This pamphlet is an exhaustive treatise on the nature, 

 physiological and chemical properties of the seeds of 

 Abrus precatorius, called Jequirity by the South Ameri- 

 cans, and used to cure granular lids. As is now well 

 known through de Wecker of Paris and Prof. Sattler, this 

 popular remedy of the South Americans produces, when 

 used as an infusion and applied to the conjunctiva, 

 severe ophthalmia, in the course of which granular lid 

 (trachoma) is brought to cure. In India it is used by the 



natives for subcutaneous injection into cattle, wherewith 

 to produce a kind of septicaemia and death. The nature 

 of the poison has been thought by de Wecker and Sattler, 

 and later by MM. Comil and Berlioz, to be due to a bacil- 

 lus (the Jequirity bacillus), the spores of which are derived 

 from the air ; and, although harmless at first, assume 

 pathogenic properties when grown in an infusion of the 

 Abrus seeds. It has been conclusively proved, however, 

 that this is not the case, that the active principle of the 

 Abrus seeds is present before any contamination with the 

 bacillus could have taken place, and further, that the 

 Jequirity bacillus, when freed from the infusion, possesses 

 no power of producing ophthalmia. 



Messrs. Warden and Waddell have carefully examined 

 the chemical nature of the seeds, and they find that the 

 active principle, abrin, is a proteid, closely allied to native 

 albumen, and obtainable not only from the seeds, but also 

 from the root and stem. E. K. 



A Text-Book of Pathological Anatomy and Pathogenesis. 

 By Ernst Ziegler. Translated and edited for English 

 students by Donald Macalister, M.A., M.B., &c. 

 Part II. Special Pathological Anatomy, Sections I.- 

 VIII. (London : Macmillan and Co., 1884.) 

 The enormous success that has attended the first part of 

 this work will, we feel sure, in no way abate with the 

 present volume. Like its predecessor it is a masterly 

 exposition of all that is known concerning the pathological 

 anatomy of the parts treated. In this last volume the 

 special pathological anatomy of the blood and lymph, the 

 vascular mechanism, the spleen and lymphatic glands, the 

 serous membranes, the skin, the mucous membranes, the 

 alimentary tract, the liver and pancreas, are described 

 with great clearness and thoroughness. The subjects are 

 treated in a detailed and systematic way, without incum- 

 brance with self-understood details. The illustrations are 

 very admirable, and while not profuse, are nevertheless 

 thoroughly representative. The bibliography, particu- 

 larly of the more recent works, is, in the English edition, 

 thanks to Dr. Macalister, a most valuable improvement 

 on that in the German edition. While a help to the 

 learner, it will no doubt prove also a valuable companion 

 to the teacher. E. K. 



LETTERS TO THE EDITOR 

 [ The Editor docs not hold himself responsible for opinions expressed 

 by his correspondents. Neither can he undertake to r, turn, 

 or to correspond with the writers of, rejected manuscripts. 

 No notice is taken of anonymous communications. 

 [The Editor urgently requests correspondents to keep their letters 

 as short as possible. The pressure on his space is so great 

 that it is impossible otherwise to insure the appearance even 

 of communications containing interesting and novel facts. .] 



The Late M. Dumas 

 I have received from M. Pasteur, President of the Committee, 

 a letter informing me that it is proposed to erect a statue to the 

 memory of Dumas at Alais, his native town. The name of 

 Dumas is so prominent in the history of our science that no words 

 of mine are needed in support of such a proposition, and I merely 

 express the hope that many English chemists will be willing to 

 contribute to this memorial. Subscriptions will be received by 

 the secretaries of the Chemical Society, Burlington House, 

 Piccadilly. W. H. Perkix, P.C.S. 



The Cholera Germ 



The latest enunciations of Prof. Koch from Toulon and Mar- 

 seilles concerning the relation of his "comma-shaped " bacillus 

 to cholera are so contradictory, that it is worth while to take 

 notice of them. 



Koch, as was mentioned in your last issue (p. 237), maintains 

 that the "comma-shaped " bacillus is the cause of cholera ; ar.d 



