[CONTRIBUTION FROM THE MASSACHUSETTS INSTITUTE O F
TECHNOLOGY. ]
REVIEW OF AMERICAN CHEMICAL RESEARCH. VOL. IV.
xo. 9.
ARTHURA. NOYES, Editor ; HENRY P. TALBOT, Associate Editor. REVIEWERS : Analytical Chemistry, H. P. Talbot and W. H . Walker ; Biological Chemistry, W. R. Whitney ; Carbohydrates, G. W. Rolfe ; General Chemistry, A. A. Noyes ; Geological and Mineralogical Chernistry, W. 0. Crosby ; Inorganic Chemistry, Henry Fay ; Metallurgical Chemistry and Assaying, H. 0. Hofman ; Organic Chemistry, J. F. Korris ; Physical Chemistry, H. M. Goodwin ; Sanitary Chemistry, E. H. Richards ; Technical Chemistry, A. H. Gill and F. H. Thorp.
TECHNICAL CHEMISTRY. F . H. THORP, REVIEWER
The Protection of Steam-Heated Surfaces. BY C. L,. NORTON. Engineer, No. 459, 165.-This investigatioii was made in order to show the relative efficiency of various kinds of steampipe covering now on the market, to ascertain the fire risk attendant upon the use of certain methods and materials for insulating steam-pipes, and to show the gain in economy attenda n t upon increase in thickness of coverings. A piece of steampipe was electrically heated from the inside, the electrical energy supplied was measured, and the amount of heat furnished was calculated. By keeping the pipe a t a constant temperature, the amount of heat supplied is obviously equal to the heat lost by radiation, convection, and conduction. T h e pipe, closed at one end by a welded-in plate and a t the other by a tight cover, was filled with heavy cylinder oil, into which the heating coil, an effective stirrer, and a thermometer, mere introduced. T h e apparatus was suspended in the middle of a room, by non-conducting cords, and the thernionieter was read by a telescope, the observer being a t a distance to avoid the production of air currents a n d the addition of heat from the person. Fourteen different samples were tested, the best results being obtained with a COVering composed of granulated cork pressed in a mould and rendered non-combustible b y a fire-proofing process. Nearly as good was a covering composed of go per cent. magnesium carbonate. A cover made of thin sheets of asbestos paper, separated from one another so a s to enclose a considerable amount of air, was also very effective. Asbestos, when not porons and not containing entrapped air, is a good conductor of heat. Carbona t e and sulphate of calcium are not good heat insulators. Cov-
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Review of American Chemical Research,
erings containing wool, hair-felt, or wool-felt, have high efficiency as non-conductors, but are considered dangerous on account of fire risks. Computations of the money saving effected by covers, show that in general a cover pays for itself in a little less than a year of 3 1 0 ten-hour days ; or in four months, working 365 days of twenty-four hours each. As a protection to wooden surfaces, an asbestos board, made of corrugated asbestos paper sheets cemented with sodium silicate, was found very effective, though not remarkable as a non-conductor of heat.
Sadtler’s Reducing Agent. Leather Manufacturer, 9, 105.These are merely general remarks upon the use of hydrogen peroxide as a reducing agent for chrome tanned skins (see this Rev., 2, 106). A slightly acid bath is used, the peroxide being added in successive small portions. Commercial Moellon” Degras. Leather Manufacturer, 9, ~o.-Moellon is a degras made by the oxidation of cod or fish oil in the pores of skins from which the degras is then pressed. Abstracts of the various methods for preparing moellon, with a few remarks upon its use in tanning, make up the larger part of this article. The Liming of Soils. BY H . J . WHEELER. U. S. Dept. Agr., Farmers’ Bull. No. 77.-This bulletin gives a popular exposition of the theory and practice of using lime as a fertilizer. T h e various materials eniployed are described and their relative values compared. Many of the conclusions are drawn from the results of experiments at the Rhode Island Experiment Station where the author is the chemist. 46
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Commercial Fertilizers. N. Y. State Sta. Bull., 129, 351421; Miss. S f a . Speczal Bull., 42 and 45 ; L a . Sta. Bull., 49, 163-198 ; R.I. s t a . Rep., 1896, 211-220; N.3. Bull., 124, 48 ; A r k . Sta. Rep., 1897, 101-118; Md. Sta. Bull., 49, 105-160; P a . Dept. Agr. Bull., 33 ; Vt. Sta. Rep., 1896-97, 28-30 ; Ga. Dept. Agr. Bull., 33, I 16 ; Me. Sta. Bull., 38. The Control of the Temperature in Wine Fermentation. BY A. P. HAYNE. Cal. Sta. Bull., 117, Ig.-The causes of t h e spontaneous heating of fermenting must and methods of controlling it are considered in this bulletin. If the temperature exceeds 100’ F. the wine ferment becomes inactive ; but injurious bacteria continue to thrive. A method of cooling must, employed in France, is described, in which the must is pumped through several hundred feet of I + inch piping arranged in columns and cooled externally by water dripping upon the pipes from a tank above them. At the California Experiment Station a column composed of flat tubes 4 by 1% inches is used, the total
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length of pipe being only 43 feet. T h e pipes are cooled by a spray of water blown against them by a strong blast of air, the evaporation adding greatly to the cooling effect.
Petroleum Briquettes in Germany. BY MAX BOUCHSEIN. U. S. Consular Rep., 57, z54.-This is a description of a process patented by J. Kohlendorfer, by which petroleum refuse is worked into a solid substance for a cheap fuel. Soda lye and a saponifiable fat (such as tallow) are heated with superheated steam with exclusion of air until the saponification begins and then a fourfold quantity of petroleum refuse is added, and the mixture heated about an hour, with constant stirring, but keeping the temperature below the boiling-point of the petroleum. T h e mixture is then run into molds and solidifies on cooling. Coal-dust, saw-dust, or other combustibles may be added during the process if desired. T h e grease may be replaced by resin or resin acid if a harder product is desired. T h e product contains about 80 per cent. of petroleum oil and only 5 per cent. of noncombustible matter.
GEOLOGICAL AND MINERALOGICAL CHEnISTRY. W. 0.CROSBY, REVIEWER.
Auriferous Conglomerate of the Transvaal. BY GEO. F. BECKER. Am. J . Sn'., 155, 1g3-208.-The auriferous conglomerate of the Witwatersrand gold field constitutes the most important gold deposit ever known. A strip of country a couple of miles in width and about 30 miles in length has yielded since 1887 about $240,000,000, and only about one-fifteenth of the accessible gold has been extracted. T h e nature of this wonderful deposit is a subject of manifest interest to geologists and ruining engineers, who, however, have arrived at various conclusions. No considerable doubt exists that the conglomerate is a marine littoral deposit, but some observers have held that the gold is detrital, being an original part of the conglomerate ; others that it is a chemical precipitate from the ocean in which the pebbly beds were laid down ; and still others that the precious metal reached the uplifted but uncemented gravel in solution, so that the ore-bearing strata are allied to ordinary veins. After presenting all the more striking facts which it is necessary to consider in testing the theories propounded to account for the deposition of gold on the Rand, the author rigidly tests each theory by the facts and reaches the conclusion that the deposition of the gold was in no sense chemical, that there are no valid objections to the theory of marine placer origin, and that no noteworthy features are left unexplained by this theory. T h e argu-
