584 



NA TURE 



[October 20, 1892 



The sixth and final lecture deals with the electrical phe- 

 nomena of muscle and with a very curious group of fishes 

 termed " electrical." 



The arrangement of the book is excellent, yet we are 

 inclined to think that it shares with many other works on 

 physiology one common fault. What we all want to 

 know more about is the life and activity of the organism, 

 and the physiologist very rightly spends much of his 

 time in experimenting in every conceivable way, 

 and generally with isolated parts of the organism. 

 His apparatus is often of the most varied and intri- 

 cate kind, and his experiments yield him definite re- 

 sults. Many of these results, however, are at present of 

 little value in shedding light on physiological processes, 

 and should not, we think, obtain the prominent position 

 they now occupy in the text-books. To take an example, 

 the experiment to demonstrate the muscle curve, in which 

 the muscle is isolated and stimulated electrically, is one 

 of the stock experiments minutely described in every 

 text-book. In this experiment the muscle is separated 

 from its antagonistic muscles, stimulated in quite an un- 

 natural way, and the result of the experiment is totally 

 different from what takes place in a contracting limb. 

 It is certain that in nearly every text-book the reader will 

 find that from this and similar experiments he is apt to 

 obtain incorrect and misleading ideas. He no doubt 

 learns something regarding very interesting electrical ma- 

 chinery, but very little physiology. Of recent years far 

 more attention has been bestowed upon the movements of 

 muscles in the limbs, and comparative physiology is at 

 last asserting its influence. It is to be hoped that when 

 this knowledge finds a more prominent place in text-book 

 literature, " muscle and nerve physiology," in the proper 

 sense of the term, will be more satisfactorily taught. 



Returning to what more exclusively concerns Prof. 

 McKendrick's book, we may point out a slip on page 8i, 

 where it would appear that the muscle sound corresponds 

 in pitch to the fundamental tone of a body vibrating 

 19*5 times a second, instead of to one vibrating at twice 

 that rate, and that Prof. McKendrick does not inter- 

 pret this sound on the lines followed by Helmholtz and 

 others. On page 91 the modern view of a "cell" is 

 represented in a drawing, and the nucleus has inadver- 

 tently been omitted. On page 31 a long and short cir- 

 cuiting key is represented, while a simple key is described 

 in the accompanying text. These, however, are but 

 trivial faults to find in an excellent little work, which is 

 most admirably got up and beautifully illustrated by 

 nearly one hundred excellent figures. 



The reader will, we think, obtain a good insight into a 

 department of physiology, and will be stimulated to 

 further research in the literature of this interesting sub- 

 ject. J. B. H. 



PLUMBING. 

 Principles and Practice of Plumbing. By S. Stevens 

 Hellyer. (London : George Bell and Sons, 1891.) 



THOSE who are acquainted with Mr. Hellyer's larger 

 book on domestic Sanitation, " Dulce Domum," 

 will not find much new matter in the present volume, but 

 NO. II 99, VOL. 46] 



the subjects are treated less discursively, and are fairly 

 well brought down to date. 



There is no trade which has been more discussed in 

 recent years than that of plumbing, and if plumbers are 

 not impressed with a sense of their responsibilities, it is 

 certainly not the fault of the architects and engineers 

 who employ them. The manual skill necessary to per- 

 form the most ordinary operations is in itself so difficult 

 that many workmen fail to acquire it ; and, on the other 

 hand, many experts in the details of the craft are never 

 properly educated in the principles of sanitation which 

 are necessary to make their work effectual from a sanitary 

 standpoint. It is the combination of both kinds of know- 

 ledge in the writer which makes Mr. Hellyer's books of 

 exceptional value. It matters little whether it is an archi- 

 tect on one hand, or a working plumber on the other, who 

 studies them, because they are of equal value and of 

 equal interest to both. The present handbook is specially 

 valuable in these respects because most of the informa- 

 tion upon matters of practical workmanship is given con- 

 currently with the reasons which should control the details 

 and the principles which should be in evidence when the 

 work is finished. 



No one unacquainted with the practical difficulties 

 which frequently crop up in sanitary practice can realise 

 how much knowledge and experience is necessary to 

 overcome them. Houses in London often present the 

 most puzzling problems, and an intimate acquaintance 

 not only with the principles and practice of the subject, 

 but also with all the most recent appliances, is required 

 for their successful solution. The ventilation of all the 

 different parts of a complicated drainage system, in- 

 cluding that which is necessary to prevent the syphonage 

 of traps, sometimes requires an amount of thought and 

 attention which a layman would think was uncalled for 

 in the face of its apparent simplicity. It is no wonder 

 that there are frequently failures to meet the highest 

 standard of excellence, especially when incompetent 

 persons are employed to design and superintend 

 the necessary operations. On the other hand, there 

 are thousands of houses in London in which no 

 such difficulties occur, and in which the drainage 

 and plumbing arrangements ought not only to be 

 extremely simple in themselves, but intelligible to the 

 ordinary householder. When such cases are entrusted to 

 a builder, or an intelligent plumber, the first requisite is 

 the manual skill required to carry out the various details, 

 and this must be acquired by the workman through ap- 

 prenticeship, or from his having acted as the assistant 

 or " mate " of a journeyman for several years. The next 

 requisite is that he should have a clear knowledge of what 

 he is going to do and why he does it. This may be ac- 

 quired to a great extent from his being familiar, in his 

 capacity as a workman, with the designs of an architect 

 orengineer under whose directions he has been employed, 

 and it is to such men that Mr. Hellyer's text-book should 

 be specially valuable. By studying its pages he will 

 avoid many mistakes. He will know what sort of joint 

 to make, what kind of trap to avoid, how to secure the 

 traps from syphonage, and how generally to complete his 

 work so as to pass the latest standards of excellence. We 

 can equally recommend it as a text-book for architects 



