122 



NATURE 



{June I, 1876 



SCIENTIFIC SERIALS 



The Journal of Mental Science, April, 1876. — Reflex, auto- 

 matic, and unconscious cerebration, a history and a criticism, by 

 Thomas Laycock, M.D., is continued and completed in this 

 number. The paper is very interesting. Dr. Laycock takes 

 great pains, and is, we think, successful in making good his 

 claim to priority over Dr. Carpenter in certain views of an ad- 

 vanced nature, which, if they are not already, will soon be 

 entirely absorbed in others much more advanced. — Dr. John 

 M. Diarmid writes in high praise of morphia in the treatment of 

 insanity, when administered subcutaneously. — Dr. Daniel Huck 

 Tuke gives an historical sketch of the past asylum movement 

 in the United States, doing full justice to the enlightenment and 

 humanity of American physicians, while recording the outstand- 

 ing difference between them and their English brethren in the 

 principle and practice of non-restraint. — A modest but suggestive 

 paper on the use of analogy in the study and treatment of men- 

 tal disease, is contributed by Dr. J. R. Gasquet. — Dr. P. Maury 

 Deas describes a visit to the Insane Colony at Gheel, where the 

 accumulating experience of a thousand years has produced an 

 instinctive aptitude to manage the insane worth more in practice 

 than the best of our consciously-formed systems. — Dr. Isaac 

 makes some interesting observations on general paralysis. — 

 "Arthur Schopenhauer : his Life and his Philosophy," by Helen 

 Zimmern, is reviewed in a manner worthy the book and its sub- 

 ject. — The Journal contains other reviews, clinical notes and 

 cases, news, &c. 



Zeitschrift der Oestcrreichischin Geselischa/t fiir Meleorologie, 

 Feb. I. — In this number appears the first part of a paper by Dr. 

 W. Koppen, on the yearly periods of probability of rain in the 

 northern hemisphere. It is accompanied by a valuable diagram 

 of curves. He begins by calling attention to the value of the 

 system on which his calculations are based, namely, the mere 

 registration of the days of which rain falls in each locality. Con- 

 sideiing that in our latitudes changes of vapour tension and of 

 relative humidity do not concur, it is simpler than measuring 

 the quantity of rain or snow. The probability of a downfall 

 depends upon two conditions, the degree of relative humidity 

 between, say 100 and 3,000 metres altitude, and the favourable 

 or unlavourable circumstances for the formation of an ascending 

 current, or, firstly, on the rate of decrease of temperature with 

 height ; secondly, on the slope of the ground towards the direc- 

 tion of the wind, while the quantity depends also on the quan- 

 tity of vapour contained in a volume of air, and so, cceleris 

 farihus, on the temperature. lie then gives a detailed account 

 of the authorities from whom he has derived his materials. The 

 selected stations are well distributed over the greater part of the 

 I'orthern hemisphere, including the North Atlantic, and have 

 tno>t of them afforded records during more than ten years. As 

 in his former writings on the subject, he represents graphically 

 the means of groups of neighbouring stations having similar 

 annual distribution of rainfall, but annexes a table showing the 

 actual numbers for each station. The diagram exhibits the 

 probability of rain in each month for each district. 



Feb. 15. — In this number Dr. Koppen concludes his remarks 

 on the yearly periods of probability of rain. The paper, which 

 is illustrated by elaborate tables, contains much valuable infor- 

 mation respecting the times of year at which rain is most and 

 least probable in a great number of countries and districts of 

 the northern hemisphere. 



Gazzetla Chiviica Italiana, Anno VI., 1876, Fascicolo I. — 

 Synthesis of the sulpho-tannic acids, by Hugo Schitf. The 

 author in this paper treats of phenol-sulphuric anhydride, 

 trichlorhydroquinone-sulphuric acid, sulphopyrogallic acid, sul- 

 photannic and pentacetosulphotannic acids, the sulpho-acids of 

 phoroglucin, &c. — On the elasticity of metals at different tem- 

 peratures, by G. Pisati. In this paper the author investigates 

 the elasticity of iron and steel, arriving at the following formula :— 



P.L ^{\ -f- gQ ^ P.U _J 



7 Trro^. /' I -f- a/ 



K-- 



where K is the modulus of elasticity of stretching force, P the 

 weight which acting on the length of wire Z, produces the 

 lengthening /, a is the co-efficient of linear expansion. — Modifi* 

 cation of the process for the extraction of alkaloids in poisoning 

 of the viscera, by F. Selmi.— On a method of detecting traces of 

 phosphoric acid in toxicological researches, by F. Selmi. — Go 

 the use of phyllocyanine as a reagent, by Guido Pellagri, — 

 Action of iodide of allyl and zinc on oxalic ether, by E. Patemo 



and P. Spica. — Chemical researches upon twelve coloured solids 

 found at Pompeii. — The remainder of the part is occupied by 

 extracts from foreign journals. 



SOCIETIES AND ACADEMIES 

 London 



Royal Society, May 4.— " On the Origin of Windings 

 of Rivers in Alluvial Plains, with Remarks on the Flow of 

 Water round Bends in Pipes," by Prof. James Thomson, LL.D., 

 F.R.S.E, Communicated by Prof. Sir William Thomson. 

 F.R.S. 



In respect to the origin ot the windings of rivers flowing 

 through alluvial plains, people have usually taken the rough 

 notion that when there is a bend in any way commenced, the 

 water just rushes out against the outer bank of the river at the 

 bend, and so washes that bank a-vay, and allows deposition to 



occur on the inner bank, and thus makes the sinuosity increase. 

 But in this they overlook the hydraulic principle, not generally 

 known, that a stream flowing along a straight channel and 

 thence into a curve, must flow with a diminished velocity along 

 the outer bank, and an increased velocity along the inner bank, 

 if we regard the flow as that of a perfect fluid. In view of this 

 principle, the question arose to me some years ago, Why dors 

 not the inner bank wear away more than the outer one? We 

 know by general experience and observation that in fact tLe 

 outer one does wear away, and that deposits are often made 

 along the inner one. Horw does this arise ? 



The explanation occurred to me in the year 1S72, mainly as 

 follows : — For any lines of panicles taken across the stream at 

 different places, as A^Bj, AgBj, &c., in Fig. 2, and which may \te 

 designated in general as AB, if the line be level, the water pres- 

 sure must be increasing from A to B, on account of the centri- 

 fugal force of the particles composing that line or bar of water ; 

 or, what comes to the same thing, the water-surface of the river 

 will have a transverse inclination rising from A to B. The water 

 in any stream line c d e ^ at or near the surface, or in any case 

 not close to the bottom, and flowing nearly along the inner bank, 

 will not accelerate itself in entering on the bend, except in con- 



• This, although here conveniently spoken ot as a stream-hne, is not lo 

 be supposed as having really a steady flow. It may be conceived of as an 

 average stream-line in a place where the flow is disturbed with ed dies or 

 by the surrounding water commingling with it. 



i 



