194 



THK INDIA. RUBBER WORLD 



Maki II 



'905- 



In view of these particulars, therefore, it is apparent that the 

 various rubbers should receive individual treatment. For ex- 

 ample, the softer sorts of Africans should not be subjected to 

 the same degree of heat as Pard. This is mentioned for the 

 reason that many factories have but one dry room for washed 

 rubber, which is frequently filled with diiTerent kinds and 

 grades. An African rubber should be dried slowly. It will 

 also be found that the strength and elasticity of such grades as 

 Lopori and Congo will be conserved by keeping them out of 

 hot water, using cold water only in cleansing and sheeting. 



As to the future for the African product— should one consider 

 the subject from the viewpoint of Mr. Georg Waldau, who 

 wrote so interestingly in your January issue, on the '•Extinc- 

 tion of African Rubbers " — there would appear little prospect 

 for improving either method or quality. But Africa is a huge 

 continent, its resources undeveloped, and the samecupidity that 

 n 5w seems bent on destroying the source of rubber supply for 

 the sake of quick returns, will, later on, protect it that it may 

 continue to be a source of revenue. 



Cambridge, Massachusetts, January 7, 1905, 



CARBON TETRACHLORIDE AS A SOLVENT. 



BY WILLIAM K. DOERFLINGER. 



CARBON tetrachloride is a heavy, colorless, transparent, 

 mobile liquid, having a neutral reaction. Its taste is 

 pungent, aromatic, and cooling. Its odor is agreeable and aro- 

 matic, resembling that of chloroform. 



It is non inflammable and non explosive. Its vapor does not 

 take fire, but it has the remarkable property of tinting a blue 

 flame green and the green flame as intense blue. The vapors 

 do not support combustion, but act in the reverse as a fire ex- 

 tinguisher. A few drops placed upon a burning alcohol lamp 

 or on a wick of a burning candle extinguishes the flame at 

 once. 



The specific gravity of Carbon tetrachloride is 1.6 ; the boil- 

 ing point 77° F. The liquid is insoluble in water, diluted alco- 

 hol containing less than 75 per cent, by volume of absolute 

 alcohol and also in glycerine and the glycerides. It is freely 

 soluble in acetone, glacial acetic acid, oleic acid, liquid carbon- 

 ic acid and aqueous solution of carbolic acid, ethyl, and amyl- 

 ic alcohol, chloroform and spirits of chloroform, carbon di- 

 sulphide, benzol (benzene), ether and spirits of ether, aniline, 

 oil of turpentine, petroleum and all petroleum products; also 

 in fixed and volatile oils and oleoresins. 



Carbon tetrachloride is itself one ol the greatest of solvents. 

 It dissolves oils, fats, resins, wax. India-rubber, Gutta-percha, 

 ceresin, spermaceti, paraffin, stearin, varnish, paints, asphal- 

 tum, pitch, balsams, coal tar, pine tar, and soda and potash 

 soaps. It also dissolves salicylic acid, carbolic acid, iodine, 

 bromine, iodoform, bromoform, menthol, thymol, camphor, 

 camphor monobromate, naphthalin, etc. It furthermore dis- 

 solves several gases, among others ammonia and hydrogen 

 sulphides. It is not acted upon by the strong mineral acids 

 and is not decomposed by an aqueous solution of potassa, 

 which will, however, remove any carbon disulphide or hydro- 

 gen sulphide present. An alcoholic solution of potassa con- 

 verts it into a mixture of potassium chloride and potassium 

 carbonate. 



Carbon tetrachloride is by nascent hydrogen gradually con- 

 verted into chloroform, and by still further reduction into 

 dichlormethane or methylene bichloride. 



It is strongly recommended as an extracting medium. It is 

 important to remember that in contrast with benzine, gasoline, 

 etc. Carbon tetrachloride (C CI,) is a chemical unit or indi- 



vidual, and in its recovery from the extracted fats, grease, etc., 

 it is always obtained as the same chemical combination, with 

 the self same properties; whereas in benzine or gasoline there 

 are unavoidable losses to be sustained, particularly the valu- 

 able, very volatile parts, so that with a continued use of ben- 

 zine the remaining less valuable ingredients, the heavier oils, 

 must finally be enriched by important additions of fresh ben- 

 zine or gasoline. 



It may be objected, that, in spite of the undeniable advan- 

 tage of Carbon tetrachloride, its present high price forms an 

 insuperable obstacle to its extended use. A superficial com- 

 parison ol the commercial values of difTcrent solvents would, 

 at first, seem to favor the lower price solvents in preference to 

 Carbon tetrachloride, and yet such acceptation is not warran- 

 ted. 



Although the prime cost at current prices of the amount of 

 Carbon tetrachloride necessary to establish an extracting plant 

 upon a running basis is indeed much higher than that of ben- 

 zine, gasoline, or Carbon disulphide, the losses incurred in the 

 use of the Carbon tetrachloride and the expense for steaming, 

 condensing water, labor, etc., employed in the recovery are so 

 much less than with either the other mentioned solvents that 

 even in the face of the high price of Carbon tetrachloride the 

 work may be performed at a greatly reduced cost, and without 

 fire risk. 



Again, it must not be overlooked that the oils and fats ex- 

 tracted are obtained in the highest degree of purity, absorbing 

 none of the extracting medium whatever, not even the odor, 

 which is most difficult to avoid in the employment of some 

 grades of benzine, gasoline, and particularly with carbon disul- 

 phide. 



It is particularly important in the manufacture of oils, from oil 

 seeds, since the residue from the oil seeds, the so called oil 

 cake, is not particularly relished by the animals to which it is 

 supplied as food, when it contains the contaminations incident 

 to the use of carbon disulphide. As a consequence the cakes 

 are more diflicult to dispose of than those extracted by Carbon 

 tetrachloride. 



An apparatus already installed for the recovery of the sol- 

 vents, does not need to be remodeled for the recovery of Car- 

 bon tetrachloride, and since the distillation process may be 

 likewise carried through in the customary manner, there are 

 no expenses attending a trial of this new solvent. 



Another remarkable property of Carbon tetrachloride is that 

 it does not in the least affect the colors of fabrics. The most 

 delicate colors, even aniline colors of silk, satin, laces, etc., are 

 not affected in the slightest degree. A mixture consisting of 

 equal parts of turpentine and Carbon tetrachloride cannot be 

 ignited at ordinary temperatures. A mixture of 60 per cent. 

 Carbon tetrachloride and 40 per cent, naphtha is likewise non 

 inflammable at ordinary temperatures. 



Carbon tetrachloride is shipped in steel drums holding 650 

 and 1400 pounds, although smaller packages usually can be 

 obtained from the manufacturers for experimental purposes. 



In a report on the French automobile trade, the American 

 consul general at Paris, Mr. John K. Gowdy, writes: "Some 

 interest is now being given to the construction of light and 

 heavy motor vans for the delivery of goods, and it is anticipat- 

 ed that a great deal of business is to be done in this branch of 

 the industry, there being more firms, no doubt, in need of con- 

 veyances for the delivery of goods to customers than private in- 

 dividuals needing cars for touring. The city of Paris now has 

 street sweepers, fire engines, post-office vans, and dust carts 

 propelled by motor." 



