December 27, 1894J 



NA TURE 



197 



Kastern Hindu Rush, giving a brief sketch of the physio- 

 graphy of the region. Prof. T. G. Bonney and Miss C. 

 A. Raisin furnish notes on the rocks collected by Mr. 

 Conway, from which it appears that the majority much 

 resemble those of the Alps. The most interesting 

 . pecimens are a peculiar schist with secondary mica, a 

 piedmontite-schist, and a fragment allied to pseudo-jade. 

 Mr. \V. F. Kirby identifies the butterflies, Dr. A. (i. 

 Butler the moths, and Mr. \V. B. Hemsley the plants. 

 Df the last about a dozen were obtained at or o%-er 16,000 

 feet. The well-known Saxifraga oppositijolia was 

 gathered at 17,000 feet, and another species (the highest 

 habitat) at 17,320 feet. Mr, \V. L. H. Duckworth writes 

 on two skulls brought from Nagyr, and Prof. C. Roy dis- 

 cusses Mr. Conway's notes on mountain sickness, coming 

 to the conclusion that the primary cause of it is asphyxia. 

 Mr. Conway's observations agree with those of other 

 experienced climbers, that a man in good condition begins 

 to feel the effect of increased altitude at about 16,500 feet. 

 The fact that he is sensible of more inconvenience when 

 in a hollow among the peaks than when on an exposed 

 ridge, Prof. Roy attributes to some loss of oxygen by the air 

 when it has passed over a considerable tract of melting 

 snow. Mr. Conway has made valuable additions to our 

 knowledge of the geography and physical history of this 

 remote mountain region, and the present volume supple- 

 ments the more popular account of his travels, which 

 appeared earlier in the year. 



The Royal Natural History. Edited by Richard 

 Lydekker, B.A., F.R.S. Vols. i. and ii. (London: 

 Frederick VVarne and Co., 1S93-94. ) 



Ar.ouT twelve months ago (Nature, vol. xlix. p. 220), in 

 a short notice of the two first parts of this work, we 

 heartily recommended it as worthy of the notice of our 

 readers. On a careful perusal of the two volumes now 

 before us, which equal one-third of the projected series, 

 we still feel quite justified in our recommendation; 

 the illustrations are for the most part extremely good, 

 and the text is not only interesting, but it is also intelli- 

 gently written. 



The first of these volumes treats, in fifteen chapters, 

 of the Primates, the Chiroptera, the Insectivora, and the 

 Carnivora, as far as the dogs. We would especially 

 notice the chapters on the cats and the dogs, as having 

 information well up to date. Instead of the olten-quoted 

 old stones, it is refreshing to meet with accounts of the 

 habits of these animals, taken from the writings of 

 V. Ball, Blandford, Guillemard, Hudson, and Sterndale. 

 Thus, in the account of the common Indian mungoose, 

 we hnd mention of the results, to within the last year or 

 two, of Mr. Espent's experiments of introducing this 

 little carnivore to Jamaica. The sugar-planting industry 

 in this island was threatened with destruction on account 

 of the swarms of rats ; within three or four years after the 

 introduction of the mungoose the rat plague came to an 

 end, and the beneficial results to the island exceeded 

 ^150,000 a year. Volume ii. commencing with the 

 bears, finishes the Carnivora, and describes the hoofed 

 mammals. The illustrations play so important a part in 

 these volumes, that we would suggest that the compara- 

 tive sizes of the figures should always be given, and when 

 possible the reader should be told where the figures first 

 appeared. 



Kitchen Boiler Explosions. By R. D. Munro. Pp. 44, 

 (London : Charles Griffin and Co., 1895.) 



The time having again arrived when domestic boilers 

 will be a source of trouble to paterfamilias, Mr. Munro 

 comes forward with an account of a series of ex- 

 periments with red-hot kitchen boilers, apparently re- 

 printed from the Transactions of some Society. Whether 

 this be so or not we do not wish to inquire, but to us it 

 seems that the diagrams of steam-pressure are little 

 NO. 1313. VOL. 5 1] 



suited to the " intelligent householder" for whose edifi- 

 cation they are intended. The chief conclusions drawn from 

 the experiments are that (l) a dead-weight safety-valve 

 should be fitted to every boiler ; (2) water will flow into a 

 red-hot boiler although there is no free outlet, and, also, 

 that a steam-pressure can be attained in such circum- 

 stances sufficient to cause rupture of the strongest boilers 

 in use ; (3) whilst a very high steam-pressure may be 

 generated in a red-hot boiler by the sudden injection of 

 cold water, a disastrous explosion cannot thus be pro- 

 duced; (4) an explosion, in the true sense of the word, 

 cannot occur unless the boiler contains water as well as 

 steam. Probably the perusal of Mr. Munro's book will 

 help to diminish the disasters from boiler explosions. 



The Island of Aladeira, for the Invalid and Naturalist. 

 By Surgeon-General C. A. Gordon, M.D., C.B. Pp. 

 no. (London : Baillicre, Tindall, and Cox, 1894.) 



Persons who are fortunate enough to be able to leave 

 England during the dreary months of winter, and who 

 select to sojourn in Madeira — " The Flower of the Ocean " 

 — should take this brochure with them. The character- 

 istics of the people and the place are concisely stated, and 

 there is more information on the geology, meteorology, 

 zoology, and botany of the island than is usually given 

 in guide-books of a similar kind. It is well known that 

 Madeira has an extensive fauna and flora, and we agree 

 with the author that it is a matter of regret that the 

 island has no public museum where they could be collected 

 and investigated. Prof. Smitz, however, is gradually 

 forming such an institution at the college in Funchal. 



LETTERS TO THE EDITOR. 



[ The Editor does not hold himself responsible for opinions ex- 

 pressed by his correspondents. N, it her can he undertake 

 to return, or to correspond with the 'Writers of, rejected 

 manuscripts intended for this or any other part of NatiJRE. 

 No notice is taken of anonymous communications.] 



" Acquired Characters." 



Now that the correspondence on this subject, which you 

 all )wed me to start in your number of Nuvemlier i, seems 

 drawing towards a close, I ask leave through you to ihank your 

 correspondents for their courtesy in replying to my inquiries, 

 and also to make a few observations by way, so far as I am con- 

 cerned, of conclusion. 



As none of your correspondents has found any fault with the 

 conditions which I suggested as essential to a good definition, 

 1 conceive that I may assume them to be correct. 



Furthermore, as none of these writers has adopted or defended 

 any of the definitions which Weismann appeared to me lo give 

 or 10 sujigest, or ha^i said anything hy way of criticism on my 

 strictures on these dtfinilions, I think that I may conclude that 

 I was not far wrong in those strictures, and that WVismann's 

 writings do not aiTord any good definition of the words to which 

 he has given currency. 



Mr. I'oulion has suggested that a definition may be found in 

 the statement that "whenever an organism reacts under an 

 external force, that part of the reaction which is diiectly due to 

 the force is an acquired character." But surely this is difficult 

 of application : for in every case of a reacliim on an external 

 stimulus there are twoelements — viz. first, ihe internal capacity to 

 respond, and secondly, the external force or stimulus. Each of 

 these is necessary lo the result and to every part of the result, 

 and neither is of it<elf sufficient to the re.-uli or to any part of 

 the result. How then can we analyse or break up the result or 

 the reaction into two parts, and say that the one is the direct 

 result of the external (ore ■, and the other is either not lis result 

 at all, or its indirect result? Where there is the j.nnt action of 

 two causes, each necessary hut neiiher sufficient of itself, I 

 conceive that you cannot either logically or pliysically sever 

 any part of the result from the action of tioth of llie causes, and 

 there is no ground for aiiriliuting directness to one part of the 

 the elTecl, and indirectness to another. Mr. I'oulion dwells 

 truly on the reaction having two causes — the internal and the 



