Dec. 20, 1877] 



NATURE 



151 



experiments performed in the same direction by M- 

 Gayon. He mcloses the apples in vapours of chloroform, 

 ether, and carbon disulphide, and his results agree with 

 those of the first observers. The chloroform and ether 

 act in the same manner as the carbolic and hydrocyanic 

 acids ; the carbon disulphide in the same way as camphor, 

 permitting partial fermentation only, 



A Problem in Chemical Affinity.— In his work on 

 "Gasometric Methods," Prof. Bunsen details an interesting 

 series of experiments on the phenomena accompanying 

 the explosion of hydrogen and carbon monoxide with a 

 volume of oxygen insufficient for its complete combustion. 

 From the results he deduces the conclusion that the ratio 

 between the products of combustion (HgO : CO2) can 

 always be expressed by small whole numbers (i : 2, i : 3, 

 I : 4, &c., and that it alters suddenly from one figure to 

 the next by gradually increasing the amount of hydrogen. 

 Deeming the nine experiments upon which the con- 

 clusion was based as insufficient for the establishment of 

 a general principle, Prof. Horstmann, of Heidelberg, 

 describes in the Verhandlungen des heidelb. naiurf, med. 

 Vereins, an extensive series of observations designed to 

 test the truth of the law. Among his results the follow- 

 ing facts are of interest. In exploding CO with gradually 

 increasing quantities of H, + O, while the ratio between 

 H and CO increased from o'25 : i to 2*33 : I, the ratio 

 between HgO and COg gradually increased from 08 : i to 

 4"5 : I, with no evidence of a predilection for rational 

 numbers. Experiments on a mixture of CO and H, 

 with gradually increasing amounts of O, led to the same 

 results, showing no such regularity in the division of O 

 between the two combusiiWe gases as Bunsen's law would 

 indicate. When aqueous vapour is present in the mixture 

 less H and more CO unites with O, while the presence 

 of COg reverses the case. By gradually increasing the 

 amount of O in the explosive mixture, it was noticed 

 that the ratio between the resultant HoO and CO^ in- 

 creased until it attained a maximum, when 35 per cent. 

 of the combustible gases were oxidised, and then sank 

 regularly to the ratio denoting complete combustion. 

 The oxygen appears to be divided among the two gases 

 ^curding to the following law : — The ratio between the 

 resultant HgO and CO2 is equal to the ratio between the 

 residual H and CO multiplied by a co- efficient of affinity 

 which is independent of the ratio between the combuitible 

 gases but dependent on the relative quantity of O present. 

 This co-efficient of affinity varied between 4 and 64, 

 showing that always more H relatively than CO is con- 

 sumed, and hence that the affinity of O to H is greater 

 than that to CO, 



Halogen Derivatives of Amines. — An attempt has 

 frequently been made by chemists to replace the hydrogen 

 in the hydrocarbon group present in amines, by CI, Br, 

 or I. These efforts have hitherto resulted simply in the 

 substitution of the basic H atoms of the amine by 

 halogens — as C2H5.NCI2 — or in complete decomposition. 

 A. Michael {^Berl. Ber,, x., 1644) has devised a method 

 for accomplishing this end, which consists in first replacing 

 these basic H atoms by acid residues, and then exposing 

 to the action of a halogen ethyl-phthalimide, 



CoH,(CO)2N.C2Hs, 

 yields in this way with Br a tribromo-ethyl-phthallmide. 



Double Salts with Cyanide of Gold.— C. G. 

 Lindbom publishes in the Univ. Arssh'ijt of Lund an 

 exhaustive account of these compounds, which may be 

 regarded as salts of the two acids, HCy.CyAu and 

 HCy.CyAu.Cy2 + ^2^q-> neither of which, however, can 

 be obtained pure for analysis on account of their tendency 

 to decompose. Most of the auro salts unite directly with 

 a molecule of the halogens ; for example aurocyanide of 

 sodium, NaCysAu, forms bromo-auricyanide of sodium, 

 NaCy2AuBr24-2aq. Aurocyanide of ammonium, AmCygAu, 

 is decomposed at 100°. 



The Fourth Nitrobenzoic Acid. — Prof. F. Fittica 

 has discovered lately a new nitro-benzoic acid, making 

 the fourth of the isomeric acids, which has been contested, 

 by other chemists, especially as it fails altogether to 

 harmonise with the theories at present accepted in 

 regard to the structure of benzene derivatives. In the 

 October session of the Deutsche chemische Gesellschafr, 

 he strengthens his position by announcing the discovery 

 of a fourth nitro-benzaldehyde, obtained by the action of 

 H2SO4 on benzaldehyde and ethylic nitrate, which on 

 oxidation is changed into th? new nitrobenzoic acjd, 

 C0H4NO3.COOH. 



Influence of Isomerism on the Formation 

 OF Ethers between Acids and Alcohols.— In 

 the September session of the Russian Chemical 

 Society, Prof. H. N. Menschutkin presented an elabo- 

 rate paper on this subject based on observations of 

 the formation or acetic ethers. The process consisted in 

 inclosing molecular weights of an alcohol and acetic acid 

 in glass tubes, immersing it in a glycerine bath at 154° for 

 a certain time, and then rapidly cooling it, and titrating 

 the unaffected acetic acid with baryta water. The results 

 show that in regard to the rapidity and limits of etherifi- 

 cation, the primary alcohols are sharply divid-'d from the 

 secondary, and the latter from the tertiary ; and the satu- 

 rated alcohols from the non-saturated. A regular decrease 

 in the rapidity coincides with an increase in the mole- 

 cular weight of the ale >hol. As in many other series of 

 experiments, methylic alcohol shows considerable devia- 

 tions from the laws governing its higher homologues. In 

 the case of non-saturated alcohols the rapidity is less than 

 that of the corresponding primary alcohols, but greater 

 than that of the corresponding secondary alcohols. 



Phosphides of Tin. — Since the introduction of 

 phosphorus bronze, the compounds of phosphorus and the 

 metals are receiving more attention. S. Natanson and 

 G, Vortmenn describe {Berl, Ber., x. 1459), several 

 methods of preparing phosphides of tin, viz., throwing P 

 on molten tin, melting a mixture of vitreous phosphoric 

 acid, charcoal, and tin, and passing phosphorus vapours 

 over molten tin in a hydrogen stream. These processes 

 all yield a crystalline silvt-ry white compound, containing 

 from i^ to 3 per cent, of P, and leaving on treatment 

 with HKO a residue of pure SnP, 



Chemical Action of Light. — In a late number of 

 the Annales de Chimie et Physique, M. Chastaing ad- 

 vances, in connection with a variety of observations on 

 this topic, the theory that the chemical action of the 

 various coloured rays on inorganic substances is depen- 

 dent on refrangibility, blue and violet acting as reducing 

 agents,' red and yellow causing oxidation. Prof, H, W, 

 Vogel attacks this opinion vigorously in the last session 

 of the German Chemical Society, claiming that the nature 

 of the substance causes the action to be one of reduction 

 or oxidation. The union of H and CI, which takes place 

 so rapidly in violet light, is regarded as purely analogous 

 to oxidation, and he alludes to Timiriazeff's late experi- 

 ments, showing that the reduction of COg by plants, 

 proceeds more rapidly in red light than in green, 



NOTES 

 At the meeting of the Royal Society, oa Thursday Ia«t, the 

 Times states, tbe following were elected foreign members: — 

 Marcellin Berthelot, of Paris ; Joseph Decaisne, of Paris ; Emil 

 Dubois Reymond, of Berlin ; Adolph Wilhelm Hermann Kolbe, 

 of Leipsic ; Rudolph Leuckart, of Leipsic ; Simon Newcomb, 

 of Washington ; and Pafnutij Tschebytschow, of St. Petersburg. 

 By this election the foreign list of the society is made up to its 

 full complement of fifty members. 



Mr. Alexander Agassiz, it is understood, proposes to spend 

 the winter in the prosecution of scientific research in the Florida 



