December 15, 1892] 



NATURE 



147 



In the chapter on blood and lymph a fuller account of 

 leucocytes with their varieties and functions, and 

 especially of the proteid and other substances associated 

 with them, would certainly have been desirable. It is of 

 course easy, in reviewing so small a book, to find in- 

 stances of curtailment and of omission, but the life history 

 of the leucocytes is of supreme importance medically, 

 that even the account of the derivatives of haemoglobin 

 might, for their sake, have been shortened. 



The phenomena of muscular contraction are well 

 described, and the account of muscle and nerve currents 

 is especially clear and to the point. 



In the chapter on the vascular mechanism two tracings 

 of pressure in an artificial schema are taken from Prof. 

 Foster's text-book. The tracings are accurately repro- 

 duced. In the description of these we are told that, after 

 a high peripheral resistance is introduced into the circuit, 

 "the pressure on the arterial side at first rises with every 

 beat till it has attained a certain height, where it remains 

 stationary, merely oscillating with every stroke of the 

 pump. The venous manometer, on the other hand, shows 

 no rise of pressure, and its oscillations becomes less and 

 less, till they disappear and the flow becomes con- 

 tinuous.'' A glance at the tracing shows, however, that 

 there is a rise of pressure on the venous side, and more- 

 over a maintained rise. This is a very important point 

 about the tracing. A student grasps readily the action of 

 the arterial blood pressure in forcing the blood from the 

 aorta to the capillaries, but he is at a loss to understand 

 why it comes back again from the capillaries towards the 

 heart. It cannot be too much insisted on that we have a 

 pressure, a small and gradually falling pressure, in the 

 veins, and that this is the important determining cause of 

 the venous flow. The author, in this the proper place to 

 bring this prominently forward, leaves it out entirely, 

 though it is incidentally referred to later on, and leads 

 the student to suppose that the presence of the valves in 

 the veins and the aspiration of the thoracic movements, 

 important though they may be, are the chief factors. 



The subject of endocardial pressure and of the pulse 

 is treated, clearly and concisely, in the light of Hiirthle's 

 important work. This is particularly welcome, as, if I 

 am not mistaken, this is the first occasion that these 

 researches have been brought before English readers. 



In the discussion of the causation of the heart's beat 

 it does not seem clear why " the beat always starts in 

 the sinus" when we are told that the sinus contracts 

 feebly and slowly. The fact that the sinus has a more 

 rapid rhythm than the other chambers of the heart, and so 

 initiates the whole cycle, is not distinctly brought out. 

 The author follows Schmiedeberg's opinion in stating 

 that muscarin acts by stimulating the nerve-endings of 

 the vagus. This is by no means certain, and we should 

 have welcomed some mention of Gaskell's opinion that 

 its action is a direct one on the muscular tissue, and some 

 of the reasons for taking that view. In the description 

 of the vasomotor mechanisms I have found no adequate 

 statement of the important part vaso-dilator nerves play 

 in regulating the circulation in skeletal muscle. 



In the account of the nervous mechanism of respiration, 



which is well up to date, in including some of the results 



of the work of Head, we should have expected also some 



statements of Marckwald's observations on the influence 



NO. 1207, VOL. 47] 



of section of the medulla above the respiratory centre. 

 No reference seems to be made of the influence of im- 

 pulses reaching the respiratory from higher centres of the 

 brain. It is also unfortunate that when the student turns, 

 as directed, lo Fig. 6i he finds that the tracing selected 

 of the efi'ect en the respiration of section of the vagi does 

 not show the increase in amplitude as it does the decrease 

 in rate, although he is told that both the changes are 

 brought about. On page 266 there is an obvious mis- 

 print ; the word "expiratory" should be "respiratory." 

 On page 291 there is another misprint, "Bj" in the 

 equation should be, of course, " Br." A few lines further 

 on there is, however, a serious error. We read, " From 

 the amount of nitrogen given off the amount of urea pre- 

 sent in the urine, may be calculated. 35 '5 c.c. of nitrogen 

 correspond to one gram of urea." The theoretical 

 amount calculated for one gramme of urea is 3727 c.c. 

 at standard temperature and pressure, while 35 '5, or 

 more exactly 35*4 c.c, is the amount which Hiifner found 

 was actually liberated not by one gramme, but by one 

 decigramme of urea. 



The chapters on the special senses and on the central 

 nervous system are some of the best in the book. The 

 methods of tracing fibres in the cord and brain are fully 

 gone into, so also is localization of function, and indeed 

 the account of the brain throughout is very clear and 

 good. 



At the end of the book is a short appendix, in which is 

 given a description of apparatus purely physical in nature. 

 Every teacher will agree with the author that it is not 

 only desirable, but necessary, to put this in a manual of 

 physiology. The ignorance of the construction and use 

 of the simplest physical apparatus, which the average 

 medical student carries with him into the physiological 

 laboratory, is usually almost as perfect as it can be. Much 

 of the time of a demonstrator of physiology has at first 

 to be given to the teaching of some of the simplest 

 physical methods. L. E. S. 



APPLIED MECHANICS. 

 Elementary Manual on Applied Mechanics. By Prof. 

 Jamieson. (London : C Griffin and Co., Limited, 

 1892.) 



THIS is the latest addition to the series of books 

 introduced by Prof. Jamieson during the last few 

 years. Like his useful work on the Steam Engme, it is 

 the outcome of the course of lectures which he delivers to 

 his own students. It is replete with the many mechanical 

 contrivances to be found in the workshop, one chapter 

 being devoted to the consideration of the screw-cutting 

 lathe alone. 



The illustrations, with which the book abounds, and the 

 necessary descriptions of the various machines considered, 

 are all that one may wish for. 



An excellent feature of the book will be found in the 

 manner in which, after having enunciated a principle, the 

 author has applied it to some well-chosen examples. In 

 this direction he has proceeded to an extent which will 

 be highly appreciated by the student. Further, he has 

 availed himself of any opportunity to obtain results ex- 

 perimentally, and these form a very instructive series of 

 examples for the young engineer. 



