Aligns/ 12, 1880] 



NATURE 



349 



with numerous analyses of soil which give to this part a great 

 importance for agriculture. The third part deals with erratic 

 blocks as to their composition and ongni ; the fourth part 

 describes subsoils, and contains a description of Lake Leman. 



Jurassic Rocks of the Altai Mountains.— According to 

 the researches of M. Schmalhausen, noticed in the Memoivs 

 (Ti-oudy) of the St. Petersburg Society of Naturalists, vol. 

 X the fossils of the Kouznetzk Carboniferous basin in the 

 Aitai Mountains, which fossils were described until ^ now 

 as palaeozoic by Goppert in Tchikhatcheff's "Travels, by 

 Eichwakl, and by Heinitz in Cotta's " Altai," are identical with 

 the Jurassic (Bathonian) plants which Heer has recently described 

 in the Jurassic Flora of Eastern Siberia and Amour. M. 

 Schmalhausen describes them as Phyllothera, Asplmium whit- 

 Heme tenuis, Pterophyllum inflexum, PoJozanisks lanceolatus, 

 Lindl., Bmchyphyllum, and Czckanowskia rigida, Heer. 



Miocene Flora.— In his work, "Die Miocene Flora von 

 Sakhalin," just published by the St. Petersburg Academy of 

 Sciences, Prof. Schmidt describes 74 species of plants he has dis- 

 covered, of which 43 were formerly known in other countries, 

 and 31 are new ; 27 are identical with Arctic Tertiary plants, 25 

 with Swiss, iS with those of Alaska, and 21 with those of North 

 America. The eighteen Alaska species are the most common of 

 the Sakhalin Miocene flora, which circumstance, as well as the 

 intermediate characters of the Tertiary flora of Kamchatka, is 

 a new argument in favour of Asia, having formed, with America, 

 one continent at this geological period. It is important to observe 

 that the Tertiary flora of Sakhalin has more likeness to that of 

 Greenland, of Spilzbergen, and of Switzerland, than to that of 

 Central Siberia ; thus, out of the eighteen species of Tertiary 

 plants discovered by M. Lopatin on the banks of the Choulyra 

 River (not far from Krasnoyarsk), none were found among the 

 Miocene fossils of Sakhalin, whilst the Tertiary flora of the 

 southern shores of Lake Baikal is very like that of Sakhalin 

 and of Alaska. To explain these differences Prof. Schmidt 

 supposes that the fossil plants which are all described by Heer 

 as Miocene ought to be considered as belonging to an older sub- 

 stage, all the more that the Sakhalin plant-beds are very inti- 

 mately connected with the marine chalkw'hich they concordantly 

 cover. 



CHEMICAL NOTES 



The influence of sewage on potable waters is again being 

 discussed. Herr R. Emmerich— in Bied. Ccntralblatt—m^^% 

 an original contribution to the subject. He has for a long time 

 daily drunk from a half to one litre of water from one of the 

 Munich brooks which receives sewage of every kind ; he has 

 satisfied himself that there were cases of typhoid in some of the 

 houses which drained into the brook. No bad effects having 

 followed the consumption of this beverage, Herr Emmerich 

 invites other experimenters to pursue investigations similar to 

 his own ! The same observer, however, finds that sewage 

 water produces death in rabbits when injected subcutaueously 

 in quantities of from 6 to 60 c.c, rabbits of a similar size 

 being killed by the injection of 200 c.c. of distilled water. 

 The injection of the residue from the evaporation of 500 c.c. of 

 sewage water produced strong convulsions and death in rabbits. 

 He proposes that suspected water may be examined by injecting 

 40 to 80 c.c. under the skin of a full-grown rabbit ; if no rise 

 of temperature greater than l' occurs, or if death does not 

 quickly follow the injection, the water would probably be unin- 

 jurious to human beings drinking it. 



Citric acid has been formed synthetically by Grimanx and 

 Adam. The process, which is described in the Comples rendus, 



/COoH 

 consists in forming dichloracetonic acid CHoCl — COH<' ^,jj-^j-.j 



from symmetrical dichloracetone, itself produced from glycerin 

 through the intermediate stage of dichlorhydrin. By saponifying, 

 by means of hydrochloric acid, the sodium salt of dichloracetonic 

 acid, citric acid is produced ; this synthesis confirms the generally 

 accepted structural formula of citric acid. 



DOUDT as to the elementary nature of sulphur is expressed by 

 Th. Gross because of recent experiments wherein he claims to 

 have produced a black, nonoxidisable, chemically indifferent 

 substance by heating perfectly pure sulphur with linseed oil, 

 dissolving the product in sulphuric acid, and precipitating by 

 sulphuretted hydrogen.' 



The influence of very small quantities of foreign substances 

 in modifying processes of chemical change is a subject of much 

 interest to the chemist, although as yet no full explanation has 

 been given of this class of phenomena. In the course of his 

 researches at high temperatures Victor Meyer has given one or 

 two instances of such reactions. Thus he finds that ferric 

 chloride, aluminium chloride, and zinc chloride are decomposed 

 with evolution of chlorine at much lower temperatures when 

 the vapour-density apparatus is previously fUled with nitrogen 

 gas than wlien no foreign gas is present. Meyer cannot trace 

 any connection between the temperature, or amount of decom- 

 position, and the chemical nature of the foreign gas. 



The long-protracted discussion between Berthelot and Wurtz 

 regarding the dissociation of the vapottr of chloral hydrate 

 appears at length to be closed ; Berthelot admits in the Coinples 

 rendus that the va]30ur is partly dissociated at 100', and that if 

 the pressure is small the dissociation is probably complete. 



An interesting experiment, and one likely to lead to further 

 results, is described by Berthelot in the Covtpt:s rendus. He 

 finds that such unstable compounds as ozone, hydrogen peroxide, 

 &c., are not afl:ected by sonorous vibrations of the rapidity of 

 100 and 7,200 per second. 



M. Meunier claims, in Comptes rendus, to have produced 

 spinel crystals, and thinks he has also produced periclase and 

 corundum by the action of steam on aluminium chloride, at a red 

 heat, in presence of magnesium. 



Among other results accruing from V. Meyer's recent deter- 

 minations of vapour densities is the .addition of six or eight sub- 

 stances to the small list of gaseous metallic compounds. From 

 the densities, and analyses, of these compounds the foUowmig 

 numbers may be deduced as representing the smallest possible 

 z-a/CTij of the element placed opposite each number :— Arsenic, 

 2 ; cadmium, 2 ; copper, 2 ; iron, 4 ; indium, 3 ; tin, 2 ; zinc, 

 2 The formula of stannous chloride is shown by Meyer to be 

 Sn.,Cl4 at about 700% but SnCU at 900°. Hence the valency of 

 tin'varies at different temperatures. 



In the last number of \.hs Berliner Bei-ichte3.-a attempt is made 

 by Wiebe to trace a connection between the atomic weights of 

 elements and the molecular weights of carbon compounds, and 

 the coefhcients of expansion of the same substances. He shows 

 that for many elements the ratio between the reciprocal of the 

 number obtained by multiplying the atomic weight of an element 

 into the mean coefficient of cubical expiession from o to 100 , 

 and the heat required to raise unit weight of the same element 

 from absolute zero to the melting-point, is a nearly constant 

 number. For elements crystalising in the regular system the 

 mean value of the constant is 2-6 ; other elements show consider- 

 able divergences. For certain classes of carbon compounds the 

 following equation is shown to hold : ^". T=n. const., where 

 A = molecular weight, a = mean cubical expansion from 0° to 

 100° </ = density of liquid compound, r= absolute boiling- 

 point and n - number of atoms in the gaseous molecule of the 

 compound. The constant for the fatty acids and ethereal salts 

 is from 3 I to 3-8. 



In the Proceedings of the Asiatic Society of Japan R. W. 

 Atkinson gives the results of his analyses of several Japanese 

 porcelain clays; these results show that the opinion of H. 

 Wurtz, viz., that Japanese porcelain is prepared from decom- 

 posed felspathic rocks alone, without admixture of kaolin, is not 

 Generally correct. Many of the clays analysed by Atkinson 

 rontained from S4 4° 59 per ce^t. of silica with 26 to 32 

 per cent, of alumina; others ag.ain contained from 7 j to 79 

 per cent, of silica. In the clays exhibited in the Philadelphia 

 Exhibition Wurtz found only one containing less than 74-5 

 per cent, of silica. 



In a series of papers by Nilson, and by Nilson and Pettersson, 

 in the last number of the Berliner Berichte, important additions 

 are made to our knowledge of the rarer earth metals. ine 

 existence of ytterbium seems proved. The atomic weight ot 

 this metal is 173 (mean of seven closely-agreeing determinations) 

 assuming the formula of the oxide to be Vb.Ps. Ihe cnier 

 reasons for this formula are the isomorphism and gener.il analogy 

 of the sulphates of ytterbium, erbium, and didymmm ; the close 

 analo-y between the selenite of ytterbium and the selemtes of 

 metals which form oxides of the formula M.,03, and the mole- 

 cular heat and molecular volume of Yb.Pa compared with the 

 same constants for the group M2O3. 



