142 



NATURE 



[June 9, 1S92 



showing apparently that they change into the more stable or 

 ketonic form when heated. The refractive and dispersive powers 

 of these compounds confirm the magnetic rotations. The 

 magnetic rotation and the refractive and dispersive powers of 

 ethyl )8-amidocrotonate show it to be an unsaturated compound. 

 — The origin of colour : ii. The constitution of coloured nitro- 

 compounds, by II. E. Armstrong. The author has previously 

 maintained that colour is conditioned by a quinonoid structure 

 in the case of azo-dyes, such as the rosanilines, methylene-blue, 

 &c. This view is clearly seen to be recommending itself to 

 chemists. Nietzki makes reference to the quinonoid character 

 of a number of dye-stuffs, although he does not seek to apply 

 buch a view at all generally. The author considers that, in the 

 case of coloured compounds which have been fairly well studied, 

 it is so generally true that a quinonoid formula is applicable, 

 that the reconsideration of the formula of any coloured substance 

 is warrantable if it do not come within the rule. The term 

 " quinonoid" must, however, beunderstoodtoincludecompounds 

 of the type of benzil, and in the case of closed chain compounds, 

 it appears to be essential that at least one of the quinonoid carbon 

 atoms be associated with a dyad radicle, and that the ring itself 

 be unsaturated. The presence of two ortho- or para-carhonyl 

 groups in a saturated ring apparently does not condition colour. 

 Nitro-compounds as a class do not come within the suggested 

 colour-rule. It is well-known, however, that nitro-compounds 

 are not all coloured, many which are commonly described 

 as yellow, being obtained white if prepared with care ; 

 from this it follows that the nitro-group does no\. per j'i? condition 

 colour. This is confirmed by a comparison of ortho- and para- 

 nitrophenol. The ortho-compound is intensely yellow, very 

 volatile, and insoluble in water ; paranitrophenol is colourless, 

 non-volatile with steam, and fairly' soluble in water. Such a 

 difference as this can hardly be ascribed to a mere change in the 

 relative positions of the radicles. The difference is rendered all 

 the more striking when the substances are contrasted wuh 

 the methcxy-compounds prepared from ortho- and para-nitro- 

 phenol. These two substances are colourless, and agree as closely 

 in their general properties as do most isomeric compounds con- 

 taining the same radicles. It therefore appears justifiable 

 to represent orthonitrophenol by a quinonoid formula — 

 C6H4 : O . NOgH, and to term it quinoneorthonitroxime. 

 As only para- and ortho-compounds can have quinonoid 

 formulae, it would follow that metanitro-derivatives must be 

 colourless ; actually, however, metanitraniline has an intense 

 yellow colour, but gives a colourless benzoate. The present 

 view of its constitution therefore requires revision. — The origin 

 of colour, iii. Colour as an evidence of isodynamic change : the 

 existence of isodynamic acids, by H. E. Armstrong. The author 

 applies the colour-rule dwelt on in the preceding paper to the 

 cases of the coloured substances known as paradihydroxytere- 

 phthalic acid, dihydroxypyromellithic acid, and the corresponding 

 " diamido" acids. These may be represented as quinonoid com- 

 pounds, thereby accounting for their being coloured. Such 

 substances as these readily change in type, yielding derivatives 

 which may be colourless owing to conversion into an isodynamic 

 form. — Studies on isomeric change. No. iv : Halogen derivatives 

 of quinone. Part i., by A. R. Ling. Paradichloroquinone on 

 bromination does not yield metadichlorodibromoquinone, as 

 stated by Hantzsch and Schniter, but the normal product, 

 paradichlorodibromoquinone. Contrary to the statement of 

 Levy, this latter substance does not furnish chlorobromanilic 

 acid on treatment with alkali, but a compound of one molecular 

 proportion of chloranilate and two of bromanilate. Metadichloro- 

 quinone on bromination at a high temperature yields paradi- 

 chlorodibromoquinone, but at ordinary temperatures the normal 

 product, metadichlorodibromoquinone is chiefly obtained. A 

 number of new compounds are described. — Halogen derivatives 

 of quinone. Part ii., by A. R. Ling and J. L. Baker, Chloro- 

 tribromoquinone is prepared by brominating monochloroqijinol 

 and subsequently oxidizing the product. On treatment with 

 alkali, it generally yields a molecular compound of the composi- 

 tion C6ClBr(ONa)202,2C6Br2(ONa)202 ; 1 2H2O. Trichloro- 

 bromoquinone is obtained by brominating trichloroquinone. 

 On treatment with soda, it yields the compound C(jClo(ONa)202, 

 2CsClBr(ONa)20„ ; loiHaO.— The crystalline forms of the 

 sodium salts of substituted anilic acids, by W. J. Pope. A 

 comparison of the crystallographic dimensions of the sodium 

 salts of the brominated and chlorinated anilic acids referred to 

 in the two preceding papers shows that the crystals possess con- 

 siderable similarity. — Formation of a hydrocarbon, CigHja 



from phenyl propionic acid, by F. S. Kipping. When phenyl- 

 propionic acid is treated with phosphoric anhydride, a resinous 

 mass is obtained which contains at least three products. The 

 first of these is a hydrocarbon, Cj8H]2, which is oxidized by 

 chromic acid mixture to a quinone, CjgHioOj. The hydrocarbon 

 yields a dibromo-derivative, CjgHjQBro. The second product is 

 a substance which yields a hydrazone of the composition 



yCHg". 



C15HJ4N2. It may possibly be C6H4 ( } CHj, owing to 



^CO / 

 the fact that it seems to be formed on treating phenylpropionic 

 chloride with aluminium chloride. The third substance pro- 

 duced seems to be an organic derivative of phosphoric acid. — 

 Metallic derivatives of acetylene, by R. T. Plimpton. The 

 silver compounds of acetylene, obtained by several methods, 

 viz. by precipitation of silver acetate or ammoniacal silver 

 nitrate solutions with acetylene, on analysis gave numbers 

 lying between those required for C2Ag2,|H20, andCjAgn. ^HjO. 

 Aqueous or alcoholic silver nitrate solutions yield precipitates 

 varying in composition from 3C2Ag._>,2AgN03,H20, andCjAgfl, 

 aAgNOgjHoO. Silver sulphate solutions gave a product of the 

 composition aCaAgj.AgaSOj.HaO. Mercuric acetate solution 

 gives a white precipitate with acetylene, of the composition 

 3HgO,2C2H2, which is not explosive, and does not yield acety- 

 lene when treated with hydiochloric acid. In these two proper- 

 ties this substance differs from the precipitate obtained from 

 mercurous acetate. — Isomerism amongst the substituted thio- 

 ureas, by A. E. Dixon. The author has prepared and examined 

 the properties of isomerides of methylphenylbenzylthiourea 

 and dimethylphenylthiourea. — Note on diastatic action, by E. 

 R. Moritz and T. A. Glendinning. The authors draw the 

 following conclusions from a series of experiments on diastaiic 

 action. The attainment of a resting stage in the transformation 

 of starch by diastase by no means shows that the energy of the 

 diastase is exhausted. The energy of the " residual" diastase 

 is, in fact, very considerable, but it is lessened to a marked 

 extent by subjecting the diastase for some time to a temperature 

 exceeding the optimum one for saccharificaiion. When, how- 

 ever, it is not exposed for any length of time to a temperature 

 exceeding the optimum, it appears capable, after transforming 

 a considerable amount of starch, of transforming further quan- 

 tities to nearly the same point, when such further quantities are 

 added successively and subsequent to the attainment of the 

 resting stage in the preceding transformation. 



Zoological Society, May 17. — Prof. W. H. Flower, 

 F.R.S., President, in the chair.— Mr. W. T. Blanford, F.R.S., 

 exhibited and made remarks on the skin of a Wild Camel 

 obtained by Major C. S. Cumberland in Eastern Turkestan. — In 

 a paper on the geographical distribution of the Land-Mollusca of 

 the Philippine Islands, the Rev. A. H. Cooke showed that the 

 distribution of the different subgenera of Cochlostyla affords an 

 interesting clue to the early relations of the various islands of 

 I the Philippine group. Regarded from this point of view, the 

 central islands, Samar, Leyte, Bohol, Cebu, Negros, and 

 I Panay, with Luzon, were closely related, while Mindoro and 

 Mindanao were remarkably isolated even from their nearest 

 neighbours. An examination of the intervening seas accounted 

 j for these phenomena, the depths between the central islands 

 being inconsiderable, while Mindoro and Mindanao are sur- 

 rounded by very deep water. The Mollusca of the two ridges 

 j between the Philippines and Borneo, formed by Busuanga, 

 ' Palawan, and Balabac, and by the Sulu Archipelago, were 

 ! partly Philippine, partly Indo-Malay. Two remarkable groups 

 ! of Helix, peculiar to Mindoro, Busuanga, and Palawan, showed 

 relations with Celebes and possibly with New Guinea. The 

 I Mollusca of the Batan, Tular, and Talantse Islands were also 

 discussed. Regarded as a whole, the Land-Mollusca of the 

 Philippines were stated to contain : (l) Indo-Malay, (2) Poly- 

 nesian, (3) indigenous elements, the first decidedly pre- 

 dominating.— A communication was read from Graf Hans von 

 Berlepsch, and M. Jean Stolzmann, containing an account of a 

 collection of birds made by M. Jean Kalinowski in the vicinity 

 of Lima and lea, in Western Peru. The species of which 

 examples were obtained in the localities were eighty in number. 

 In an appendix an account of previous authorities on the same 

 subject was added. — Mr. G. A. Boulenger gave an account oY 

 Lucioperca marina, a rare species of fish, originally described 

 by Pallas from the Black Sea and the Caspian, and little known 

 of late years. — A communication from Mr. Oldfield Thomas 



NO. II 80, VOL. 46] 



