448 



NATURE 



{Sept. 9, 1880 



Prof. Silva remarked that the influence of diluents may have a 

 contrary effect from that of water-vapour, and that the question 

 is worth investigation. 



Metallic Compounds containing Organic Radicals, Part I., by 

 J. Sakurai. — Tlie author has succeeded in obtaining a compound 

 of methylene iodide, CPLIj, with mercurous iodide, Ilg,!^, of 

 the formula CHjIHgl. It is a white crystalline substance, 

 insoluble in water, cold alcohol, ether, chloroform, and ethylic 

 iodide. It is soluble in boiling alcohol .and in methylene iodide. 

 It melts at io8°-io9° C. 



Besides this substance, another, insoluble in all ordinary sol- 

 vents, is produced, which possesses the formula CH2(HgI)2. 

 Chlorine and bromine act on these substances, forming methy- 

 lene chlorides or bromides, and halogen salts of mercury. The 

 author proposes to attempt to produce the zinc and sodium 

 analogues of this body. 



On some Relations bet-dieen the Atomic Volumes of Certain 

 Elements and the Heat of Formation of some of their Corn- 

 founds, by Walter Weldon, F.R. S.E. — It has been observed 

 that the heat evolved by the union of chlorine with a metal is 

 greater than that of bromine, and that the heat given off Ijy 

 bromine is greater than that by iodine. In a similar manner 

 oxygen gives off more heat than sulphur. Berthelot has observed 

 that positive elements obey the same rule, but that there are 

 some exceptions caused far diverses circonstances mal connnes. 

 That the heat of combination is inver.-ely proportional to the 

 atomic weights of the reacting elements is sometimes the case, 

 but is not a general law ; but on comparing the heat evolved by 

 combination of positive elements with their volumes, a direct 

 numerical proportion is observable. To this law there are two 

 exceptions, viz. cadmium and manganese. Cadmium is usually 

 classed along with zinc and magnesium, although it closely 

 resembles indium. It compares with magnesium, but not with 

 zinc. The atomic volume of cadmium is greater than that of 

 zinc, yet the heats of formation of its chloride, oxide, &c., are 

 less than tliose of zinc. The heat of formation of indium com- 

 pounds, which have not yet been observed, should be greater 

 than those of zinc. In the same way the heats evolved during 

 formation of compounds of man;^anese are greater than those of 

 iron, yet the atomic volume is less. Either this case is excep- 

 tional, or manganese does not belong to the iron group. 



In over 100 instances it has been observed that molecular 

 heats of formation of elements of the same group divided by the 

 atomic volumes of the electro-negative elements give numbers 

 either identical with, or bearing some simple relation to, each 

 other. 



After some complimentary remarks from Prof. Williamson, 

 Prof. W. Ramsay pointed out that the heats evolved by the 

 combustion of allotropic modifications of carbon and phosphor\is 

 bore the same relation to each other as their specific volumes, 

 and hinted that the heat evolved by the combination of elements 

 of the same group with other elements bore some remarkably 

 simple proportion to the relation of the number of atoms in 

 the complex molecules of the solid elements. 



On the Specific Rotatory Power of Cane and Invert Sugar, by 

 Alfred H. Allen. — The author points out that on inverting sugar 

 its weight is increased by absorption of water, and that allowance 

 is not usually made for this fact. He has therefore calculated 

 the following corrected table for Sj : — 



Sj. 



Cane-sugar ... -1- 73 '8 



Invert sugar ... - zyd at 15° C. 



Dextrose -1- 57-6 



Lcevulose... ... - ioS"S at 15° C. 



The deviation for a plate of quartz i mm. thick is under similar 

 conditions 24° for its transition tint, and 21 '66° for the sodium 

 ray. Hence the corresponding values for So may be calculated 



by multiplication by = o"9025. 



24 

 On the Identification of the Coal- Tar Colours, by John Spiller, 

 F.C..S. — The process recommended is the action of sulphuric 

 acid on the dyeing material, taken in conjunction with the shades 

 produced on, and the tendency to dye silk, wool, or cotton. 

 The most remarkable reactions are the following : — Magdala-red 

 with sulphuric acid gives a blue-black ; .Saffranin, a grass-green, 

 becoming indigo- blue on strongly heating; Chrysoidin, deep 

 orange, turning almost to scarlet on heating ; Alizarin, ruby red, 

 or maroon ; Eosine, golden yellow ; Primrose (naphthalene- 

 yellow), first yellow, then colour discharged ; Chrysaniline, 

 brown fluorescence; Aurine, yellowish brown; Atlas-orange, 



rose-colour, changing to scarlet on heating ; Atlas-scarlet, no 

 alteration ; Biebrich-scarlet, R, blue-black ; ditto, B, blue- 

 green ; Aniline-scarlet, permanent golden yellow ; Indulin, slaty 

 blue to indigo ; all violets give a yellow, or brownish yellow ; 

 Phenyl and diphenylamine blues, dark -brown solutions ; Iodine 

 and malachite greens, bright yellow solutions, the former giving 

 off iodine on heating ; lastly, Citronine, a pale cinnamon or 

 neutral tint. 



On the Density of Fluid Bismuth, by W. Chandler Roberts, 

 F.R.S., and Thomas Wrightson, C.E.— The density of bismuth, 

 just molten, was determined by a modification of the usual process 

 for determining the specific gravity of liquids devised by Mr. R. 

 Mallet, and was found to be lo'039, as a mean of three experi- 

 ments. By an apparatus termed the oncosimeter, which admits 

 of the weight of a ball of metallic bismuth being taken in 

 molten bismuth by means of a delicate spring balance, its mean 

 specific gravity deduced from six experiments was found to be 

 I0'055 ; th".t of solid bismuth is 9'S2. 



On Crystals iT/HgHSOj, by P. Braham. — Mercury, when left 

 in contact with sulphuric acid for two years, deposits extremely 

 deliquescent crystals of the above formula. 



On the Treatment of Complex Ores containing Zinc, by E. D. 

 Parnell. — The presence of zinc renders the extraction of lead 

 and copper from their ores so difficult that manufacturers reject 

 them ; nor are zinc ores containing less than 25 per cent, of zinc 

 adapted for the extraction of that metal. 



Further Notes on Petroleum Spirit and Analogous Liquids, by 

 A. H. Allen. — To distinguish petroleum spirit from shale 

 naphtha and from benzene, mix one volume of boiled carbolic 

 acid with three volumes of these liquids. The carbolic acid 

 refuses to mix with the former, but mixes with the two latter. 

 On similar treatment with coal-tar, pitch, petroleum spirit and 

 shale naphtha do not mix, whereas benzene does. With carbolic 

 acid, burning oil from shale can be distinguished from kerosene, 

 the burning oil from petroleum, for the former is not miscible, 

 whereas the latter turns violet, and partially mixes ; and if 

 warmed, crystals of carbolic acid separate on cooling. By 

 treatment with nitric acid and with bromine, it was shown that 

 naphtha from petroleum contains So per cent, of paraffins and 

 20 per cent, of olefines ; photogene, 55 '° ^° P*^"^ cent, of 

 paraffins, and that wax consists entirely of paraffins; whereas 

 shale naphtha contains 75 to 90 per cent, of olefines ; photogene 

 from the same source, 60 to 65 per cent, of olefines, and that 

 the lubricating oil consists entirely of olefines. 



On the so-called N'ormal Solutions for J'olumctric Analysis, by 

 A. H. Allen. — This communication was a recommendation that 

 the various different meanings of the term " normal " be done 

 away with, and that a normal solution be understood to be one 

 containing in 1,000 cub. cents, such an amount of reacting body 

 as will combine with, replace, or oxidise one gram of hydrogen. 



On the Determination of the Loss of Heat in Steam-boilers, 

 arising from Incrustation, by William Thomson. — This plan 

 consists of evaporating the various waters in vessels exposing an 

 equal surface of each, care being taken to keep the total amount 

 constant by means of a constant supply. After a given time 

 the remainder is measured and the ratio calculated. Deposit of 

 incrustation greatly impedes evaporation. 



On the Identification of the Ink used in writing Letters and 

 Documents as Evidence in Cases of Libel, Forgery, S^ir., by W. 

 Thomson, F.R. S.E. — The author has observed that different 

 specimens of writing give different coloured reactions with 

 various reagents, such as sulphuric, hydrochloric, nitric, or 

 oxalic acid, or by caustic soda, solutions of bleaching-powder, 

 and chlorides of tin. Such differences may be of use in detect- 

 ing forgery, for the change of colour affords evidence as to 

 whether all the ^^'riting has been performed with the same ink. 



The Effects of Magnesia on Vegetation, by Major-General 

 Scott, C.B., F.R. S.— The author's conclusion, drawn from 

 numerous experiments, is that there is overwhelming evidence 

 against the notion that soil naturally contains so much magnesia 

 that an extra supply will be of little or no benefit. There are 

 strong grounds for supposing that magnesia, like phosphoric 

 acid, is not only an essential ingredient of plants, and aids in 

 their nutriment, but also that it determines the beneficial action 

 of other ingredients. 



On the Action of Oils on Metals, by William H. Watson.— 

 Most oils attack copper and iron, but not to the same extent. 

 Some act much more on copper than on iron, and vice -jersd. 



On Bleachvig-Poioder Residues, by J. F. W. Hodges.— To 

 extract active chlorine from 10 grains of bleaching powder, so 



