Nov. 20, 1879] 



NATURE 



55 



superior varieties of rice and cotton, can only be grown 

 on good soil ; on poor soil they at once deteriorate. The 

 same may be said of live stock : the miserable native 

 breeds are accustomed to starve during a part of every 

 year; such treatment would be fatal to better animals. 

 Until good fodder crops are grown, any permanent im- 

 provement in the breeds of farm animals is impracticable. 

 We might easily extend our notice of this useful volume ; 

 it is full of practical information, and must prove of great 

 value to all engaged in agricultural operations in India. 



R. W. 



Grundriss dcr ckemischen Technologic Von Dr. Jul. 



Post. Part ii. (Berlin : Robert Oppenheim, 1879.) 



We have already noticed the first part of Dr. Post's 



excellent manual of chemical technology (see vol. xvi., 



83), which made its appearance towards the end of 1876. 



Unfortunately, the completion of the work has been 



ed by the severe and prolonged illness of the editor. 



The first portion was mainly confined to a description of 



modes of manufacture of crude or intermediate 



iucts; the second part treats of the finished or final 



products. Objections might, doubtless, be raised against 



uch a mode of treatment, but we question if, on the 



ile, a more systematic method of dealing with so 



iplex a subject as chemical technology could have 



been devised. The entire work forms unquestionably one 



e most, if not the most, complete repertorium of the 



ting processes of industrial chemistry that we know of 



in any language, and as such we can confidently re- 



ommend it to the notice of our chemical manufacturers. 



Dr. Post has been assisted by an excellent band of 



collaborators, many of whom are recognised as authorities 



n the subject of their respective communications. A 



due amount of space is usually devoted to a consideration 



of the theory of the various processes when this has been 



t all worked out; and the description of the mode in 



which these processes are actually carried into operation 



i. facilitated by numerous diagrams and plans. Dr. Post 



1, to be congratulated on the completion of an exceed- 



igly useful work. 



LETTERS TO THE EDITOR 

 I he Editor does not hold himself responsible for opinions expressed 

 by his correspondents. Neither can he undertake to return, or 

 to correspond with the writers of, rejected manuscripts. No 

 notice is taken of anonymous communications. 

 Vie 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 ensure the appearance even of com- 

 munications containing interesting and novel facts.} 



The November Meteors 

 The cloudless sky from the morning of the I2th to the 15th, 

 ihe total absence of moonlight, afforded a most favour- 

 opportunity for the observation of the meteors of the 

 A constant watch was kept up at this observatory from 

 10 p.m. until daybreak of the 13th, 14th, and 15th, and the 

 : alts show that the Leonids were considerably in excess of 

 1 .it they had been during the last few years. 

 The total number of meteors observed was 309, and out of 

 104 radiated from the Lions, and 56 clearly indicated 

 rincipal radiant points. Four of the radiants were situated 

 the stars 1, y, 8, and -q Leonis, and the fifth was just below 

 (31) Leonis Minoris. The position of this east point was very 

 ly marked by a stationary meteor of the 1st magnitude. 

 ity-six of the meteors were of the 1st or 2nd magnitude* 

 nine others were brighter than 1st magnitude stars. The 

 -t number of Leonids seen during a single hour was 

 i ram 4 to 5 a.m., on the 14th. S. J. Perry 



Stonyhurst Observatory, November 18 



The Platysomid Fishes 



I AM very sorry to find that my esteemed friend Prof. H. 



Alleyne Nicholson has, in the new edition of his "Manual of 



Palaeontology" (vol. ii. p. 138, note) committed the mistake of 

 quoting me as his authority for elevating the Platysomid fishes 

 to the " rank of a distinct division of Ganoids." No such 

 proposition occurs in the unpublished paper to which he 

 refers, which was written to follow up the views which I 

 expressed in my account of the structure of the Palxoniscida: 

 (Palseontographical Society, 1877), as to the abolition of the 

 sub order " Lepidopleurida:," necessitated by the demonstration 

 of the fact that the Platysomida; as 3. family are not really allied 

 to the Pycnodontidrc, but are on the other hand so closely linked 

 by tie- of structure to the Palseoniscidx, that, wherever the latter 

 family is placed, thither the Platysomida: must follow. 



My paper on the "Structure and Affinities of the Platyso- 

 midffi" was read before the Royal Society of Edinburgh on 

 May 5 of this year, and will in a few weeks appear in the 'forth- 

 coming fasciculus of that Society's Transactions. Prof. Nichol- 



take as to my views is obviously due to his h?.\ i 

 had, and that on one single occasion, a very hurried glance over 

 my proof-sheets. R. H. Traquair 



8, Dean Park Crescent, Edinburgh, November 12 



Voice in Fish 



The question as to whether fish have any so-called v ice or 

 means of intercommunication having some interest for your 

 readers, I may relate that about six years ago, while enyn 

 a survey of the Disang iver in Eastern Asam, I had occadon 

 to sound by a line the depth of a pool called the " Deo Dube " 

 (or deep of the Demon). 



■\Yhile seated in a small Rob Roy canoe and very slowly drifting 

 on the p.-iol, I became aware of a number of large Mahsir {Barbes 

 macrocephalus) moving about in the water below and around me. 

 Sitting perfectly still I had the pleasure to see them gradually 

 approach the surface and move about me at a foot or so , : 

 passing alongside, under and round the canoe carefully exau ining 

 it, bow and stem specially. It may not be easy to guess a Ii h*s 

 thoughts, but from the manner in w hich they examined my sym- 

 metrical and grey coloured canoe they appeared to think it might 

 possibly be a huge fish, and dead of course. 



While watching their movements I was aware of a peculiar 

 "cluck," or percussive sound — frequently repeated, on all 

 and coming from below, but close to me. Eventually I found 

 that this was made by the Mahsir, and one— passing close along 

 on my right, by itself, made several distinct sounds as it went on 

 — that seemed answered by others to the left. If seated, say on 

 the bank, the sound would be loud enough to be heard at 40 feel 

 distance. 



A large bivalve also is common in some parts of Eastern Asam 

 that sings loudly in concert. A small ant also makes a peculiar 

 thrice-repeated noise by scraping in uniton on the dry leave; of 

 its nest if it is disturbed. S. E. Peal 



Silurian Fossils in the "Lower Old Red Sandstone" 

 of the Curlew Mountain District 



Your correspondent in Nature, vol. xxi. p. 32, on the above 

 subject has evidently misunderstood the notice (Nature, vol. 

 xx. p. 641). The rocks in question, though belonging to what is 

 generally known as the " Old Red Sand-tone," contain Sill 

 fossils, which confirms the opinion of myself and others that the 

 lower Old Red should be regarded as the upper part of the 

 Silurian formation. G. Henry Kinahan, 



President of the Royal Geological Society of 



Dublin, November 17 Ireland 



The Paces of the Horse 



A GOOD many ingenious contrivances have lately been invented 

 by which to find out the true movements of the feet of the horse 

 in its various paces, notably that described in "A Stud 

 Locomotion" which appeared in Nature, vol. xx. pp. 434, 

 46S, 488. 



My object in writing this letter is to challenge the assumption 

 of all these experimenters that their diagrams should constrain 

 artists to correct their representations of animals in moti n 



When, for instance, Prof. Marey says of his diagrams, " 1 

 picture; are correct as regards the position of the members ; it 

 would be the artist's duty to add elegance of form," it is appa- 

 rent to me that such a division of labour would never produce a 

 picture. Take Fig. 16, for instance, representing the true posi- 

 tion of the legs in galloping, and I venture to say no amount of 



