:. Particulars are just to hand of a simplified method of obtaining alkali percarbonates which has been patented by M, H. Wade, of Hatton Garden, London, No. 152368. Solid alkali percarbonates are obtained by treating sodium carbonate with hydrogen peroxide in presence of sufficiently limited quantities of water to produce the solid product directly, and of sodium chloride for salting out the product. A previous calcination of the sodium carbonate, and the addition of anti-catalysers such as sodium silicate, magnesium chloride and magnesium-sodium silicate are advantageous. Messrs. Rayner & Co., will obtain printed copies of the published specification and will forward on post free for the sum of 1/- each. MEETINGS FOR THE WEEK. Saturday, January 8, 1921. NOTICES. EDITORIAL.-All Literary communications and Books, Chemical Apparatus, &c., for review or notice to be addressed to the EDITOR. 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EDITORIAL. : THE following papers have been received :- Some suggestions for a uniform system in which the names of compounds shall be connected with their formulæ, put forward in hope that the matter may claim the attention of those in the forefront of chemistry, and the possible formation of an International Congress to take up the subject upon lines similar to the Committee of Atomic Weights. Received January 6, 1921. "The Storing of Light." CORRIGAN. By J. FREDERICK The results for boron, beryllium, and silicon are given without comment in Table III. TABLE III. Element Boron (amorph.) Boron (amorph.) Boron (cryst.) 323 0.886 Beryllium Beryllium 323 1.08 O'4246 2.54 Beryllium Phosphorus (yellow) 189 Platinum 1873 0'054 0.056 0'0390 1.38 0'0398 1.39 1.70 1.68 The most interesting element in this group is iron. The value of gradually increases to 373 A, after which it diminishes. During recalescence new groupings of the atoms evidently take place for at 1173 A p is only three-quarters of its former value; i.e., there is a sudden change in the value of from 133 to 108, when iron consists almost entirely of Fe, molecules. Now it is known that iron particles are more susceptible to new groupings than the molecules of any other element. An iron bar hammered in a magnetic field becomes magnetised through the arrangement of like poles in one direction; but heat or rough usage causes these temporary groupings to break up again and they disappear or become impossible above 983 A, at which temperature there is evidently no molecular complexity. It will be noticed that nickel does not behave in quite the same way unless its critical temperature is above 900 A (as in the case of iron). To sum up (1) Elements which have abnormal specific heats (elements of low atomic weights) are just those elements whose rate of change of per degree is considerable. (2) For most elements diminishes as the temperature rises, and often, in the same group, as the atomic weight increases. An exception to the latter rule is exhibited by the triad iron, ruthenium, osmium, although this exception might disappear at the melting points (corresponding temperatures). (3) Iron appears to behave normally until its critical temperature, when it suddenly changes from a mixture of Fe, and Fe, molecules to Fe molecules. 14, (4) The values of R at the melting-points are relative to Br.. The values of RT quoted in this paper are equal to RXT The The lower the temperature the smaller does R Polymerisation amongst Compounds. Most, if not all, elements polymerise, but this property is shown more particularly by the elements in the first two rows, and they are able to exert their polymerising influence in their compounds. The results for the chlorides are given in Table XI. TABLE XI. Absolute 328 0'456 0.282 330 O'333 O'214 1.56 330 0.264 O' 173 153 SrCl2 BaCl2 RbCl Cu,Cl2 AgCl BaCl,. 2H2O ZnCl2 HgCl2 Ticl. SnCl, SnCl PbCl2 0'0911 1.48 CuFeS, Whereas the raising of FeS to FeS, increases from 162 to 190, increasing the valency has the opposite effect in the case of the sulphides of tin (cf. SnCl, and SnCl1). This might point to the presence of SnS,, SnS, and S even at ordinary temperatures, for when SnS, is heated," a portion sublimes without decomposition but the greater part is resolved into sulphur and the 139 monosulphide" (Roscoe and Schorlemmer, "Treatise on Chemistry," vol. ii., p. 846). 1'53 0'0896 1'59 O'171 2.05 0.136 1.59 0'052 1.58 0*0689 1.56 0.188 Table XIV. gives the results for the sulphates and it will be seen how the presence of oxygen and hydrogen (both polymerising agents) leads to greater polymerisation. Compound I29 | (NH,),SO. 159 Na,SO. 136 K2SO 1923 KHSO 2.00 CuSO The chlorides appear to polymerise to about the same extent as the elements composing them, but the presence of water leads to further polymerisation, the value of CaCl,.6H,O being 2.68 at 264 A. This value drops to 139 at 289° A, due perhaps, to dissociating into anhydrous CaCl, and free (liquid) water whose 's are 1.60 and 1+ respectively. Three double chlorides have the p's of MgSO. BaSO, FeSO,.7H2O TABLE XIV. 0'0827 2.29 2.67 331 O'235 PbS,O, 331 0.185 0.163 1.44 2.00 boron and for nitrates lies between the values for the chlorides and the sulphates, except in the case of ammonium nitrate. Results for a few phosphates, chromates, chlor XIX., XX., XXI. respectively. The hydrated sodium salt is less polymerisedates, and arsenates are given in Tables XVIII., than the anhydrous salt, surely a rare occurrence, although it should be pointed out that the specific heats have been supplied by different observers. The low value for the hydrated salt may be due into to partial decomposition, decomposition Na2S2O, and H2O (whose p's are 196 and 1+ respectively). I The hyposulphates are less polymerised than the corresponding sulphates owing to the substitution of a sulphur atom for a more highly polymerising oxygen atom. We should expect the borates, which contain two highly polymerising elements, oxygen, to be more highly polymerised than the sulphates, and this surmise is confirmed by the results quoted in Table XVI. Compound Na P2O, ... TABLE XVIII. Absolute {KH2PO1 Na,HPO,. 12H2O 2.52 ... 2.16 2:24 O'228 2'09 K,P2O, 1.822 0.821 2.22 |