CHEMISTRY. 



103 



form on fusion with caustic potash, from which 

 it separates on treatment with water. The ox- 

 ides of lead and tin seem to behave at high tem- 

 peratures in a similar manner. 



In a paper on the crystalline allotropic forms 

 of sulphur and selenium. Dr. Muthmann, of 

 Munich, shows that besides the well-known 

 rhombic pyramids and monoclinic prisms, sul- 

 phur may, under certain conditions, be obtained 

 in a third crystalline modification, which has 

 been termed by Gernez soufre nacre. This third 

 modification has been fully investigated by the 

 author, and in addition a fourth distinct variety 

 has been discovered. The third form is obtained 

 in brilliant tabular crystals after boiling pow- 

 dered sulphur with alcohol, filtering, and slowly 

 evaporating the alcohol. Similar crystals are 

 obtained after agitating a saturated alcoholic 

 solution of ammonium sulphide with excess of 

 powdered sulphur, and, in about four weeks' 

 time, by allowing solution of acid potassium 

 sulphate slowly to diffuse into a solution of so- 

 dium thiosulphate. These crystals are almost 

 white, and exhibit the luster of mother of pearl. 

 The crystals of the fourth form, also monoclinic 

 resembling a rhombohedron with predominat- 

 ing basal plane are best obtained by allowing a 

 solution of sulphur in alcoholic ammonium sul- 

 phide diluted with four times its volume of alco- 

 hol to evaporate at a temperature not exceeding 

 14 C. Occasionally in -this experiment all four 

 forms of sulphur are obtained. Both the third 

 and fourth forms readily change into crystals of 

 the rhombic form. It is an interesting fact that 

 the fourth form of sulphur is isomorphous with 

 the form of selenium obtained by the evaporation 

 of a hot saturated solution in carbon bisulphide. 



Four fossil resins from the coals of Kilmar- 

 nock and Methill, Scotland, are described by W. 

 Ivison Macadam. They appear in certain brown 

 scales in the coal or in layers, and can be readily 

 detected by the eye. Chloroform was employed 

 as the solvent in the first experiments, but after- 

 tests showed that the material so obtained was 

 partially soluble in ether ; and in the later work 

 the author first extracted with ether and then 

 treated the residue with chloroform. In this 

 manner the resinoid substances are divided into 

 two distinct portions. The ether-soluble resins 

 are partially volatile at temperatures much be- 

 low the boiling point of water, whence the au- 

 thor argues that they are either complex or are 

 broken up at comparatively low temperatures. 



A new disinfectant material called "thio- 

 campf," described by Prof. Emerson Reynolds, 

 is based on the liquid which is formed when sul- 

 phur-dioxide gas is brought in contact with cam- 

 phor, in which several powerful substances are 

 dissolved. The mere exposure of the liquid in 

 a thin layer to the air determines the steady 

 evolution of relatively enormous volumes of sul- 

 phur-dioxide gas, charged with the vapors of 

 powerful disinfectants. These gases and vapors 

 will in due time be diffused through the whole 

 atmosphere of a well-closed room, and will reach 

 everything contained therein. 



New Processes. A process has been patented 

 by Gerhard Kriiss "for decomposing commer- 

 cial nickel and its salts and galvanically coating 

 objects with pure nickel." In the preliminary 

 part of his specifications the author declares that, 



according to his experiments, metallic nickel is 

 not a chemical element, but an alloy containing 

 about 98 per cent, of a metal similar to common 

 nickel, but finer, and about 2 per cent, of an 

 element differing from nickel. The nickel ele- 

 ment is for the present designated with Ni 

 and the new element with X. Ni free from X, 

 or nickel in the new sense of the word, is pro- 

 duced from common nickel, nickel salts, or di- 

 rect from the solutions of the raw materials 

 obtained by concentration smelting, by proceed- 

 ing according to the different nature of these 

 sources. It is impossible to separate it by one 

 operation, because the combinations of X are 

 soluble in Ni salts, and resist separation from 

 them. It is therefore necessary to perform sev- 

 eral operations in succession, or to repeat one of 

 them several times, to obtain pure nickel. The 

 operations, which are described, are derived from 

 certain peculiar properties of the compounds of 

 the element X. The pure nickel obtained ac- 

 cording to the author's processes is particularly 

 adapted for galvanically coating objects. While 

 ordinary nickel has a brownish-yellowish hue, 

 derived from the element X, the color of pure 

 nickel, or Ni, is decidedly more like silver. 



Benzoates of cellulose have been prepared by 

 C. P. Cross and E. J. Bevan by a process depend- 

 ing on the solubility, in strong solutions of sodi- 

 um hydrate, of the hydrated modifications of 

 cellulose precipitated from solution in the am- 

 monia copper reagent or zinc bichloride. These 

 derivatives are soluble in glacial acetic acid, 

 whence they are precipitated in voluminous 

 white flocks by the addition of water ; and are 

 fusible at high' temperatures, with sublimation of 

 benzoic acid if the heat is continued. It is a 

 noteworthy property of them that they are as- 

 similable by micro-organisms a fact which has 

 special significance in relation to any definitions 

 of cellulose involving resistance to alkalies. 

 Growing plants afford an infinite variety of these 

 hydrates, which will be more or less soluble in 

 alkaline solutions. The cellulose isolated as the 

 residue of. processes of oxidation and hydrolysis 

 must therefore be to that extent an arbitrary 

 quantity. 



The isolation of fluoroform, CHF S , the fluor- 

 ine analogue of chloroform, CHC1 3 , is described 

 by M. Merlans and by M. Chabrie. M. Merlans 

 prepared it by the action of silver fluoride on 

 iodoform, chloroform, or bromoform, and found 

 it dissolving readily in chloroform and alcohol, 

 but only slightly absorbed by water, decomposed 

 by aqueous or alcoholic potash with formation 

 of fluoride and formate of potassium; and de- 

 composed also on heating in a glass tube with 

 the production of gaseous silicon fluoride and a 

 deposit of carbon. M. Fabrie's process and re- 

 sults are similar to those of M. Merlans. 



As a colorimetric method for estimating tan- 

 nin in barks, etc., Samuel J. Hinsdale forms an 

 ' k iron mixture " of solution of potassic f errocy- 

 anide and liquor of chloride of iron, and a solu- 

 tion of tannin (pyrogallic acid). Six two-ounce 

 glass tumblers are placed on a white surface. 

 Five drops of the infusion of bark are dropped 

 into one of the tumblers, and into the others 4, 

 5, 6, 7, and 8 drops of the tannin solution. Then 

 add to each 5 cubic centimetres of " iron mixt- 

 ure"; in one minute add 20 cubic centimetres 



