January, 1915. 



KNOWLEDGE. 



19 



on documents in the Public Record Office. The seals 

 examined dated from the thirteenth to the eighteenth 

 century, and differed but Uttle froni modern sealing wax. 

 Most of them consisted of a mixture of beeswax and resin, 

 others of pure beeswax. Two seals, of the dates 1399 and 

 1423 respecti\-ely, were composed of wax, the character- 

 istics of which agi-eed more nearly with those of East Indian 

 than of European beeswax. The wax composing an im- 

 pression from the Great Seal of 1350 agreed in chemical 

 and physical characters, with pure beeswax of to-day. 

 The pigment in the red seals was vermilion, while the green 

 seals contained verdigris. 



THE BRITISH COLOUR INDUSTRY.— As the out- 

 come of the deliberations of the Committee of Chemical 

 Manufacturers, appointed in August last, under the 

 chairmanship of the Lord Chancellor, a meeting was held 

 on November 10th of representatives of the principal 

 firms engaged in industries in\-ol\ing the use of coal-tar 

 dyes. At this meeting a scheme was suggested for the 

 formation of a limited company, the capital for which was 

 to be mainly subscribed by the consumers of dycstuffs, 

 while the Government was prepared, conditionally on this 

 being done, to subscribe part of the share capital and to 

 guarantee the interest on a large issue for a certain number 

 of years. The British control of the undertaking would be 

 preserved, and steps would be taken to prevent the enter- 

 prise from interfering with other branches of chemical 

 industry. 



It was also announced that the Government was taking 

 preliminary' steps to acquire dye-producing works in this 

 country for the purpose of the proposed company, and 

 that arrangements would be made for the transfer of other 

 concerns to its control. 



The principle of the proposal was unanimously adopted 

 by the meeting, and a small committee was formed to confer 

 with tiie Board of Trade as to the methods of developing 

 a scheme upon the Unes suggested. 



THE HARDENED OILS INDUSTRY' .—The solution 

 of the problem of converting fluid oils into solid fats has 

 led to one of the most important developments of industrial 

 chemistrj' during the present centur\-. 



Although the unsaturated fatty acids in oils, typified by 

 oleic acid, will readily absorb iodine or oxygen, they 

 long resisted all attempts to make them combine with 

 hydrogen to form solid saturated fatty acids, tj'pified by 

 stearic acid, thus : — 



Qis Hsi O2 -f- Ho = C18 H36 Oo. 

 Oleic acid. Stearic acid. 



Some details of the way in which the difficulty was 

 overcome have already been gi\'en in these columns. 

 The oil is heated in a finely di\'ided state in a current of 

 hydrogen, preferably under pressure, and in the presence 

 of a metallic salt, such as a compound of nickel or pal- 

 ladium, which acts as a cataljrtic agent, and effects the 

 combination between the liydrogen and the fatty acid. 

 .4nv desired degree of hardness can thus be imparted to 

 the fat, and evil-smelling fish oils are rapidly converted into 

 hard, odourless tallows. 



Enormous quantities of hardened oils are now manu- 

 factured in Europe and the United States. In Germany 

 the largest factories engaged in hydrogenating oils are at 

 Bremen, where only edible oils are hardened to produce 

 " Brebesol " ; and the Germania Oil Works at Emmerich, 

 which produce only technical products, sold under the names 

 of " Talgol " and " Candelite," for the manufacture of 

 candles and the like. 



Interesting details of the development of the industry in 

 France are given by the Consul-General at Marseilles 

 (Diplomatic (Did Consular Report, No. 5377). The pronounced 

 rise in price of coco-nut oil has led to an increasing demand 

 for hardened oils, such as cotton-seed, sesame, and pea-nut 

 oils, for the manufacture of substitutes for butter and lard, 



in which coco-nut oil was formerly a principal constituent. 

 So far, however, the industry is only just established in 

 France, and has not met \vith as warm a welcome as in 

 Germany or America. 



The so-called " compound lard " in the United States is 

 now mainly made from hydrogenated cotton-seed oil. 

 According to Mr. E. Thomson (American Perfumer, 1914, 

 IX, 139) the total capacity of plant for hardening oils in 

 Europe is estimated at one million three hundred and 

 seventy-five thousand barrels (of four hundred pounds), 

 and the United States output at five hundred thousand 

 barrels. Deodorised coco-nut oil is also being increasingly 

 used for the purpose, in admixture with hj'drogenated oils. 



The hydrogen used for hj'drogenating fats must be of 

 a sufficient degree of purity, since traces of impurities, 

 such as chlorine, arsenic, sulphur, and phosphorus, inhibit 

 the reaction. In some of the larger works, according to 

 M. Bontoux (Les Matieres Grasses, 1914, VII. 4194), the 

 gas is obtained by the electrolysis of alkaline distilled water, 

 while in other factories it is prepared from water-gas or 

 producer-gas. In the methods of Linde-Frank-Caro and 

 of the Societe de i'AirLiquide, h}'drogen of ninety-seven to 

 ninetj'-eight per cent, purity is obtained by the fractional 

 distillation of the liquefied components of water-gas, and 

 it is then brought to a purity of 99 to 99-5 per cent, 

 bj- being passed over soda lime at 180° C. The trace of 

 oxygen still remaining in the gas is negligible. Another 

 method of preparing hydrogen for the purpose is Lane's 

 process of decomposing steam by red-hot iron, the resulting 

 iron oxide being subsequently reduced again by the elements 

 of water-gas. 



A complete plant for hydrogenating about fifteen tons of 

 oil a day costs about /15,000, and the cost of hardening 

 a hundredweight of fat ranges from Is. 2d. to 3s. 2d., 

 according to the process, the nature of the original oil, and 

 whether the hydrogenated fat is intended for food or for 

 technical purposes. 



GEOGRAPHY. 



By A. Scott, M.A., B.Sc. 



J\IUD-LUMPS. — In a recent " Professional Paper " of 

 the United States Geological Sur\-ey (No. 85 B) E. W. 

 Shaw gives an account of the remarkable clay formations 

 which occur at the mouths of the ^Mississippi, and are 

 locally designated " mud-lumps." Such an immense 

 amount of material is brought dowm annually by the 

 Mississippi, and deposited at its mouths, that land is built 

 out at an estimated rate of three hundred feet per annum, 

 and, consequently, the channels, islands, and bars are 

 constantly changing their positions. The mud-lumps, 

 however, differ from the usual delta deposits in a number of 

 ways. They occur some distance off the shore, near the 

 submarine bars at the various " passes " through the delta, 

 and form islands up to an acre in extent. Thev rise in a few 

 weeks to a maximum height of from two to eight feet above 

 sea-level, and at first are elliptical in shape, but soon become 

 irregular, owing to erosion by tide and river action, .\fter 

 attaining their maximum height, they become quiescent, 

 and finally disappear as the result of being worn down by 

 the water. Sometimes they appear to subside in much the 

 same manner as they rise. 



The central core of the " lumps " is composed of a sticky 

 bluish-grey clay, \'ery fine-grained, and containing little 

 of the coarser delta deposits. Surrounding this are various 

 beds of sand and silt, which have been thrust up in an 

 anticlinal fashion by the rise of the core. The whole is very 

 much fissured and faulted, but the clay itself is structureless, 

 and contains practically no organic remains. .'Apparently 

 connected ^\^th the fissures are numerous active mud- 

 springs, which discharge salt, " sludge," and gas. The gas 

 is mainly methane, with subordinate amounts of nitrogen, 

 oxygen, and carbon dioxide, and seems to be formed by the 

 decomposition of organic material. 



