37^ 



NATURE 



{August 8, 1878 



experiments which sccin to point strongly towards a 

 negative answer. 



An interesting paper on the respiration of the frog is 

 contributed by Prof. Martin, whose observations strongly 

 suggest a close relationship between the nervous centre 

 ■which regulates respiration and that which regulates 

 general reflex action, even if the two should not be iden- 

 tical. He discusses the question whether there be two 

 independent, though closely related, nervous centres, one 

 for inspiration and the other for expiration, or whether, 

 as supposed by Budge, there is a single centre from which 

 the muscles of inspiration and those of expiration may 

 receive their innervation according to circumstances. 

 Dr. Martin shows that this latter hypothesis does not 

 hold good for the frog, and that in it there are really two 

 distinct centres, one for inspiration, and one for expira- 

 tion, each having its own stimulus, and generating its 

 own nervous impulse, which can travel in them only to 

 its own set of muscles quite independently of the resistance 

 opposed to discharge from the other centre. 



Those who arc interested in the electro-motive proper- 

 ties of muscle will find in this journal an admirable report 

 on this subject by Prof. Burdon Sanderson, in which he 

 gives an account of Hermann's recent work in this de- 

 partment of animal electricity, along with such informa- 

 tion both regarding modes of investigation and experi- 

 mental results as greatly facilitate comprehension of the 

 subject. 



A most laborious and fatiguing series of experiments 

 has been made by Mr. North on the effects of starvation 

 with and without severe labour, and on the elimination of 

 urea from the body. These experiments were made upon 

 himself, and, in addition to the personal discomfort pro- 

 duced by a complete abstinence from food, he voluntarily 

 underwent severe exercise upon the treadmill, for the 

 purpose of ascertaining exactly the effect of labour upon 

 the excretion of urea. Flint had found that in the case 

 of Weston, the pedestrian, the excretion of urea was con- 

 siderably increased during a long walk, and Mr. North's 

 observations go to show that severe exercise does increase 

 the elimination of urea, but the increase is very small, 

 Ijoth when the person is fed upon ordinary diet, and when 

 nitrogenous food is entirely Mithheld. The quantity of 

 urea passed, however, depends largely on the condition 

 of the body at the time, varying according to the greater 

 or smaller reserve of nitrogenous material contained in it, 

 and he thinks that Weston, before entering upon his 

 walk, had accumulated a large reserve, from which the 

 urea he excreted was derived. 



The paralysis produced by potash salts when injected 

 into the circulation, is usually ascribed to a special action 

 upon the muscles and heart. Dr. Ringer and Mr. 

 Murrell, however, from a number of experiments on the 

 subject, have come to the conclusion that potash has no 

 special affinity for muscle, but is a protoplasmic poison, 

 having an equal affinity for all protoplasm, and destroy- 

 ing the tissues in the order of their vital endowments. 



Mr. Langley has made a number of observations upon 

 the salivary glands, and finds that Nussbaum's supposi- 

 tion that the disappearance of the black colouration 

 produced by osmic acid from the sub-maxillary (?) gland 

 after treatment with glycerine is not due to the removal 

 of ferment from the gland, but to some other cause, and 



that furthermore an amylolytic ferment does not exist at 

 all in the sub-maxillary gland of the rabbit. He finds 

 that there is a marked difference between the cat and the 

 dog in regard to the salivary secretion, the sympathetic 

 secreting nerves having a different connection with the 

 gland cells in the two animals, a difference which favours 

 the paralysing action of atropia in the cat. 



The secretion of sweat is now known to be, like that of 

 saliva, directly under the control of the nervous system, 

 and to be excited by secreting nerves, independently of 

 alterations in the vessels which supply secreting glands. 

 Dr. Ott and Mr. Field show that the nerve centres in 

 connection with the sweat glands can be stimulated by 

 the poison muscarine, and that a greater amount of 

 carbonic acid than usual in the circulating blood will also 

 excite functional activity, a fact which would tend to 

 explain the greater tendency to sweat which people 

 observe when they are shut up in a close room, a ten- 

 dency which appears to be greater than can be readily 

 accounted for by the warmth of the room alone. 



These brief observations will give some idea of the 

 variety of physiological subjects discussed in the Joia-nal 

 of Physiology, and we heartily congratulate the able 

 editor and his co-operators on the importance and interest 

 of the results set before us in the numbers which have 

 already appeared. We have no doubt that in such com- 

 petent hands this journal will continue to maintain its 

 high character, and, while absolutely indispensable to all 

 who desire to follow the progress of physiology, it will, 

 we think, do much to diffuse a knowledge of that science 

 amongst general readers. 



A UNIVERSAL GEOGRAPHY 

 Stanford'' s Compendiicm of GeograpJiy and Travel, based 

 on Hellwald's '^ Die Erde nnd ihre Poiker." Africa: 

 Edited and extended by Keith Johnston. Central and 

 South America : Edited and extended by H. W. Bates, 

 With Ethnological Appendices by A. H. Keane, B.A. 

 Maps and Illustrations. (London : Stanford, 1878.) 



HELLWALD'S "Die Erde und ihre Volker" is well 

 known in Germany, and has achieved a great 

 popularity. We doubt, however, if a simple translation 

 of Hellwald's work would have been either fair or wise ; 

 for though it is written more brilliantly than German 

 works usually are, and although Hellwald himself is a 

 competent geographer, it has several drawbacks which 

 we should have regarded as serious defects had they 

 been permitted to stand in this English edition. For one 

 thing, Hellwald is a violent Anglophobist, and he takes 

 every opportunity of depreciating English travellers or 

 ignoring them altogether. We therefore think it wise in 

 the publisher of the English edition to take the German 

 work simply as a basis on which to found an English 

 work that shall fairly represent the present state of geo- 

 graphical knowledge. The method adopted by the 

 publisher appears to us well adapted to attain the end in 

 view. He has succeeded in obtaining the services of 

 geographers having a special knowledge of the various 

 divisions of the earth of which the several sections of 

 the work treat. These editors, taking the translation 

 of Hellwald as their raw material, go over it, correcting 

 and extending as far as they deem necessary in order to 



