i 22 CHEMISTRY 



recently. The ignition temperature of a mixture of hydrogen and oxygen out of contact 

 with any solid material is about 600 (Dixon and Coward, /. Chem. Soc., 1909, 95, 514), 

 and the corresponding point for a mixture of carbon monoxide and oxygen is about 

 650. Air may be substituted for oxygen without altering these ignition temperatures. 

 Reference may be made here also to further experiments by Dixon on the ignition of 

 explosive gaseous mixtures (/. Chem. Soc., 1910, 97, 661; ro.n, QQ, 589), and to an in- 

 vestigation, with a practical bearing on mine-explosions, in which the authors have 

 determined the limits of inflammability in mixtures of air with the simpler paraffin hy- 

 drocarbons (Burgess and Wheeler, /. Chem. Soc., 1911, pp, 2013). It is interesting to 

 note that the experiments of Bone and others on the combustion of gases at hot surfaces 

 have led to the development of practical methods for the raising of steam, the concen- 

 tration of liquids, and the fusion of metals (see Journal of Gas Lighting, 1911, 114, 22, 

 98; Engineering, May 1912). A general and exhaustive report on the subject of com- 

 bustion was submitted by Bone to the Chemical Section of the British Association 

 (B.A. Reports, 1910, 469). 



Mixtures of hydrogen and oxygen, submitted to the action of the silent electric dis- 

 charge at the temperature of liquid air, give under certain conditions a high yield of 

 hydrogen peroxide (Fischer and Wolf, Ber., 1911, 44, 2956). The silent discharge has 

 played a part also in the experiments of Dewar and Jones on the conditions of formation 

 and the properties of carbon monosulphide (Proc. Roy. Soc., A., 1910, 83, 408, 526; 

 1911, 8j, 574). When carbon disulphide vapour at low pressure is exposed to the silent 

 electric discharge, it is decomposed into sulphur and gaseous carbon monosulphide, 

 CS. Passed into a tube cooled with liquid air, the monosulphide is condensed, along 

 with the unchanged disulphide. If the temperature of the tube is then allowed to rise, 

 the monosulphide polymerises with explosive violence, forming a brown substance, which 

 may be formulated as (CS)x. This latter may be obtained also from thiocarbonyl 

 chloride, which reacts rapidly at the ordinary temperature with nickel carbonyl, accord- 

 ing to the equation: xCSCl 2 +xNi(CO) 4 = xNiCl 2 -f4xCO+(CS)x. 



Some other interesting inorganic substances, prepared lately, are worthy of mention 

 here. Cuprous sulphate, obtained by heating methyl sulphate with cuprous oxide in 

 the absence of water (Recoura, Compt. rend., 1909, 148, 1105), is stable in dry air, but 

 is decomposed immediately by water, with deposition of metallic copper and develop- 

 ment of heat. It is noteworthy that the existence of the compounds NHg.HjO and 

 2NH3.H2O in the solid state has been definitely proved by a study of the freezing-point 

 curve for mixtures of ammonia and water (Rupert, /. Amer. Chem. Soc., 1909, 31, 866; 

 Smits and Postma, Proc. K. Akad. Wetensch. Amsterdam, 1909, 12, 186). Another 

 interesting achievement is the preparation of solid oxygen, by the evaporation of the 

 liquefied gas (Dewar, Proc. Roy. Soc., A., 1911, 85, 589). 



Organic Chemistry. The investigation of the carbon compounds is proceeding in a 

 multitude of directions, but interest and importance attach mainly to research work 

 along one or two lines. In the synthesis of those substances which are normally the 

 products of vegetable or animal activity there is a special significance, as also in the 

 preparation and study of physiologically active compounds which find application for 

 medicinal purposes. A glance into the current chemical literature shows clearly also 

 the extent to which organic chemists are occupied with problems relating to molecular 

 structure. The general principles underlying the formation of organic compounds are, 

 it is true, well established and regularly applied in practice, but in cases where two or 

 more structural arrangements of the atoms in the molecule are possible there is less cer- 

 tainty of treatment and correspondingly greater interest attaches to their elucidation. 

 In the attack on such problems organic chemists are using physical methods to an in- 

 creasing extent, and are finding them successful where purely chemical methods have 

 failed. 



The investigation of the proteins and their degradation products, albumoses, pep- 

 tones, and amino-acids, has been actively prosecuted in recent years. In his Faraday 

 lecture on the relation of synthetical chemistry to biology (/. Chem. Soc., 1907, QI, 1749) 



