422 



NATURE 



[Afarc/i 8, 1877 



and the cell is filled with water and projected on the screen. 

 "When the tube is heated by boiling the water in the flask, the 

 jelly is liquefied, and the liberated colouring-matter rises in the 

 water, showing the direction of the heated current. — Prof. 

 Guthrie exhibited an arrangement he has been using, with a 

 view to determine the vapour-tension of water, and explained 

 the difficulties to which such a determination is liable, and the 

 manner in which his apparatus has so far failed. It was shown 

 that a crystal of alum or a saturated solution of salt, when 

 introduced into the Torricellian vacuum, depresses the mercu- 

 rial column less than pure water, whereas a solution of size, gum 

 arable, or any colloid, depresses it to precisely the same extent. 

 It thus appears that water in its different states of combination 

 has different vapour densities, and their determination requires 

 an arrangement in which the several substances can be easily 

 introduced into the Torricellian vacuum, and very slight changes 

 of the level of the mercurial column can be ascertained. Prof. 

 Guthrie has been employing a U-tube thirty-three mches long, 

 one extremity of which is bent, and terminates in a capillary 

 opening, and a bulb is formed at the U-bend. If the substance 

 under examination be introduced at the open end after the appa- 

 ratus has been filled with mercury, inverted and the superfluous 

 metal escaped, the mercury expelled through the capillary 

 opening will give a measure of the amount of the depression. — 

 Prof. McLeod suggested a modification of this form of appa- 

 ratus. — Prof. Guthrie then showed the manner in which elec- 

 tricity is distributed on non-conductors, such as the plate of an 

 electrophorus, by placing it for a given time beneath a point con- 

 nected with a charged Leyden jar, and subsequently sprinkling 

 a mixture of sulphur and litharge over it. It was shown that 

 the diameter of the circle formed below the point after the super- 

 fluous powder had been removed is not purely a function of 

 the distance between the point and the plate, but is mainly 

 influenced by the conductivity of the material, and further, that 

 if the point be directed obliquely towards the plate, the circle 

 formed is very slightly eliptical, but the elipticity is in no degree 

 proportionate to the obliquity of the point ; and finally, he 

 showed that if the non-conducting plate of an electrophorus be 

 written upon with a metal and sprinkled with the above mixture 

 of sulphur and litharge, the former or latter adheres according 

 to the nature of the metal used, and he suggested that som.e such 

 arrangement might be employed as a kind of electrical touch- 

 stone for discriminating between certain metals. 



Edinburgh 

 Royal Physical Society, February 21.— R. H. Traquair, 

 M.D., president, in the chair. — A paper was read by Dr. Tra- 

 quair, on the structure of the lower jaw in Rhizodopsis and Rhho- 

 dus. He stated that he had ascertained that the detached bone 

 hitherto considered to be the premaxilla of Rhizodopsis was in 

 reality the dentary element of the lower jaw. This bone shows 

 one large laniary tooth at its anterior extremity, behind which 

 the margin is set with a series of small teeth of uniform size. 

 Complete specimens of the mandible of Rhizodopsis show, how- 

 ever, besides the large tooth in front, several others placed at 

 intervals behind it, and internal to the range of small teeth. 

 The question was, therefore, what had become of these other 

 laniaries in cases where the dentary bone was found detached. 

 An explanation of this was afforded by an investigat'on into the 

 structure of the lower jaw in the closely-allied Rhizodus. In this 

 gigantic form the dentary element of the mandible is conformed 

 just as in Rhizodopsis, bearing one large tooth in front, the rest 

 of the margin being occupied only by smaller ones, the remain- 

 ing laniary teeth being borne by separate internal dentary pieces 

 articulated to the inner side of the dentary proper, and of course 

 liable to be dispersed and lost in cases where the elements 

 of the lower jaw had become detached from each other before 

 their entombment as fossils. Analogous accessory bones bearing 

 the large teeth of the lower jaw had previously been known to 

 exist in the dendrodont fishes of the Old Red Sandstone. As 

 regards the true premaxilla of Rhizodopsis, it was ascertained by 

 Dr. Traquair to be a very s-mall bone articulated to the front of 

 the cranial shield as in other fossil fishes of the same group. 

 Papers were read (i) on the ornithology of Yedo, by Colin A. 

 McVean, and (2) on the occurrence of the Black Redstart (Ruti- 

 cilla tithys) in Stirlingshire, by J. A. Harvie Brown. 



Berlin 



German Chemical Society, February 12=— A. W. Hof- 



mann, vice-president, in the chair. — A. Wiillner states tiiat an 



observation lately published by F. Miiller, that steam raises the 



temperature of saline solutions above 100°, was known before 



the time of Gay-Lussac, and is in no way opposed to the fact 

 that the steam evolved from saline solutions has the temperature 

 of the latter, as observed by the late G. Magnus and himself. — 

 C. Hensgen continuing his researches on the action of hydro- 

 chloric acid on sulphates, has observed the transformation of 

 blue vitriol and of sulphate of magnesia into chlorides at a red 

 heat. — M. Conrad and W. R. Hodgkinson have found that the 

 action of sodium on acetate of benzyle engenders benzyl- acetate 

 of benzyl, that is hydrocinnamate (phenyl-propionate) of 

 benzyl : — 



CH3 CH3 



i + Na = I -i- C7H7 



COaC^Hy COgNa 



Acetate of benzyl. Acetate of sodium. Benzyl. 



CH3 CH2C7H7 



1 + C7H7 =1 +11 



CO2C7H7 COgCyH^ 



Benzylacetate (or phenyl propionate) of benzyl. 

 E. Chambon states that bromine transforms fuchsine into tecra- 

 brominated rosaniline-bromhydrate Cj(,Hj5Br4N3. HBr, a fact 

 already known through the researches of Caro and Grabe. — T. 

 lobst and O. Hesse describe several constituents of coto bark : 

 paracotoin CjgHjgOg, transformed by barytes into paracotoinic 

 acid C19H14O7, and by potash into paracumarhydrine : — 

 ^19^1208 + 2H2O = CO, -f 2C9H8O3 



Para-ciimarhydrine. 

 This losing water easily yields CgHgO^ paracumarin. They also 

 describe hydrocotoin O^i^^if^Q, Cotoin C2.2Hi80g, cotonetin 

 C2oHi(;05, oxyleucotin 021^20^7' leucotin C.jiHjoOg. — H. 

 Beckurts and R. Otto prefer sulphuric acid to alkali for trans- 

 forming propionitril into propionic acid. They consider solid 

 dichloropropionitril to be polymeric with the liquid substance. 

 They likewise describe dichloropropionic acid and its transfor- 

 mation into monochloracrylic and pyroracemic acid.^ — C. A. 

 Martius gives a detailed description of the production and re- 

 fining of petroleum in Pennsylvania. 



February 26. — A. W. Hofmann, vice-president, in the 

 chair. — A. Christomanos published the result of a great 

 number of analyses of Greek chrome-iron-ore leading up 

 to the formula of R3O4 with varying amounts of CaO, 

 MgO, SiO, &c. The proportion of Cr203 and FeO varies 

 between 1:2, 2:3, i : i, and 3 : 2. — From researches by 

 K. Heumaun, it appears that the greenish powder resulting 

 from the action of nitrate of silver on ultramarine (discovered 

 by Unger) is a mixture. Thechief ingredient is yellow, but it has 

 not been analysed. — J. II. Droc'^e has determined the solubility 

 of sulphate of lime in water at various temperatures and in solu- 

 tions of various salts. — T. Moddermann published speculations 

 on atomicity. — V. Meyer denied the correctness of Ladenburg's 

 experiments and his conclusions as to the difference of N(C„H5)3 

 C7H7I and N.(C2H5)2. C-H^ . C2H5L — Br. Radziszewsky com- 

 municated that the following bodies show phosphorescence under 

 he oxidising influence of alcoholic potash : paraldehyde, metal- 

 dehyde, aldehyde-ammonia : iurfurin, hydrocinnamide, hydro- 

 cuminamide, hydranisamide, anisidin ; formic aldehyde. The 

 author calls attention to the observation of Dachenim, that 

 noctiluca miliaris acts on the skin like nettles, which have been 

 proved to contain formic acid. He thinks that noctilucse may 

 contain formic aldehyde. — R. Auschlitz has found that chloride 

 of acetyl transforms bibasic acids, viz., succinic, phthalic, and 

 diphenyl-dicarbonic acids into anhydrides, being itself trans- 

 formed into acetic acid. The same chemist, conjointly with R. 

 Schultz, has tranformed phenanthrenchinone into diphenyl-dicar- 

 bonic acid by the action of sodium amalgam by simultaneous 

 reduction and oxidation : — 



CgH^— C = CgH.— CH . OH CgH. , COOH 



I I I I I 



C8H4— C = CgH^— CH.OH C6H4.COOH 



Phenanthren-chinone. TJnknown alcohol. Diphenyl-dicarbonic acid. 

 E. Hartwig published preliminary remarks on phthalic aldehyde. 

 — H. Limpricht has found that hydrochloric acid transforms sul- 

 phonic acids into the corresponding hydrocarbons : — 



CgHgSOgH + Hcl = Q.^^^{+ SO3CI?). 



O. N. Witt, in a note on the history 01 chrysoidine, claims for 

 himself the discovery of this colouring-matter, while he acknow- 

 ledges that H. Caro has likewise prepared this substance by an 

 independent discovery. — A. Baeyer has prepared from furfurol, 

 C4H3O . COH, and acetic anhydride, a new acid : — 



C4H3O . CH = CH . COOH, 

 a furfuryl-acrylic acid, yielding a green colouring-matter with 

 phenol. With propionic anhydride a homologue is obtained. — 



