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diameter, worked automatically by a tidal clock, designed upon the alarm principle and so arranged that it actuates the penstock both for opening and closing, twice a day ; the hydraulic accumulator containing sufficient water for four actions of the penstock. The plant is designed so that the treatment can be either chemical or bacterial. I n the first case, the chemicals are added before the sewage enters the grit chambers and the three covered tanks act as settling basins; if the treatment is bacterial the covered tanks are used as septic tanks. LEONARD P. KINNICUTT.
Sewage Disposal at Shelby, Ohio. BY BENJAMIN H. FLYNN. Eng. News, 48, pp. 434-435 (~goz).-The plant consists of two sludge pits, each I O x 24 x 6 feet deep ; capacity 8,000 gallons, a settling basin nearly half an acre in area, dug in clay, the bottom and sides unprotected, and two intermittent filtration beds, with areas of 12,500 and 10,500 square feet respectively. These filters are underdrained every 30 feet with 6 inch drains ; over these underdrains the filter beds are 2 feet deep, sloping to 18 inches midway between the drains. The main filling material is bituminous coal cinder. The volume of sewage treated is from 200,000 to 300,000 gallons a day, and is a weak domestic sewage. T h e sludge pits act as septic tanks, though not designed for that purpose, and remove about 50 per cent. of the organic matter, without producing much sludge, having been cleaned out but once in a year. The peculiar feature of the plant is the large settling basin into which the effluent from the sludge pits runs, before it is carried onto the intermittent filtration beds. No odor is given off from this basin. T h e analyses given are curious, in apparently showing that nitrates are formed by septic action, also in showing that the amount of purification calculated from oxygen consumed, is very different from the amount when calculated from the albuminoid ammonia. LEONARD P. KINNICUTT. I N DUSTR I A L C H EI71STRY. Burning Coal Dust without Smoke. Iron Age, November 6, 1go2.-Describes the Bartlett and Snow Co’s. device for crushing and burning the dust. T h e coal is thoroughly dried before using, and these three paramount rules are given as the necessaries for complete combustion : ( I ) T h e coal must be of uniform size. (2) The coals used in t h e furnace must be of equal mixture, to admit of uniform combustion, and it is best that it be thoroughly dry. T h e plan of wetting coal before use, or putting a steam jet under a boiler fire, is a fallacy. ( 3 ) T h e dust must be burned in suspension, to get perfect combustion. To fulfil these objects, they crush the coal to uniform size, dry it down to 2 per cent. of moisture, pulverize to 80 mesh, and feed by a warm or spiral conveyor
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into a fan blast. Air jets spray the dust upwards against the arch of the fireplace. I n a test, 2 . 2 pounds of slack were used as dust, per horse-power-hour, against 2.85 pounds of ordinary coal fed by shoveling. J . W. RICHARDS.
The Development of the Modern By-product Coke Oven in America. BY C. G. ATWATER. Eng. Mi?z.J., Kovember I , 1902. (Paper read before A m . h s t . Mzn. Eng.)-There are now 3,413 by-product ovens in the United States and Canada, capable of producing 3,000,000 tons of coke yearly, or 13 per cent. of the total production. T h e original Otto-Hoffmann type with vertical regenerators has been improved by automatic methods of handling the coal and coke, use of electrically-operated labor saving devices, and details of construction ; at Sydney, soft coal has been compressed, producing improved coke ; at Everett and some other plants, the gases are divided, in order to obtain high-power illuminating gas. T h e Schniewind type of oveii uses the under-fired principles, and the regenerative ciianiber is entirely separated from the oven-supporting structure. Other improvements are the protection of the iron construction work froiii the radiated heat, the mechanical dressing of the brick oven walls, and the use of construction sheds provided with traveling cranes. J. TT'. RICHARDS. Electrochemistry at Sault Sainte ilarie. BY J. W. RICHARDS. Elec. Chenz. h d . , November, 1902.--A description of the power stations at this point, and of the single electrochemical industry here installed, that of the Canadian Electrolytic Alkali Co., using the Rhodiii process. T h e plant consists of three 2 0 0 kilowatt dynamos, each running 40 cells in series, and sending goo amperes through each. T h e cell is of the mercury type, the salt solution being inside a bell, while the caustic soda forms outside the bell, in an iron pan. T h e anialgani discharges itself, by contact with the irou pan. T h e whole plant can make 6. j tons of bleaching-powder, and 2 tons of caustic soda daily ; the former would supply the whole Canadian market. J. TI'. RICHARDS. The Thallium Storage Cell. BY A. I,, MARSH. Elec. C h e w 1902.-A discussion of the peculiar advantages which thallium and its oxides present for this purpose, which might be practicable if the metal were cheaper. I t costs now $6 per pound. Thallous oxide (T1,O) is soluble in water, while thallic oxide (T1,0,) is insoluble in water and in caustic potash. If a solution of the former is electrolyzed, with sheet-iron electrodes, spongy thallium separates on the cathode and thallic oxide on the anode. When the current is stopped, the cell acts as an accumulator, the two deposits going bask into the solution, and giving a potential of a little over 0.5 volt. I t is hardly possible
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that a commercial cell can be thus constructed, but the cell is very interesting scientifically. J. W. RICHARDS.
AGRICULTURAL CHEMISTRY. A Study of Some of the Salts Formed by Casein and Paracasein with Acids-Their Relations to American Cheddar Cheese. BY L. L.VANSLYKE AND E. B. HART. N . Y.State Agr. Expt. Sta. Bull. No. 214, pp. 53-7g.-The relation of acids to the changes taking place in cheese curd was investigated. I n extracting cheese with a dilute solution of sodium chloride a body was obtained which resembled in both physical and chemical properties that prepared by treating paracasein with dilute lactic acid. This salt-soluble product was always present in normal cheese, the quantity varying apparently with the amount of acid. I t was found that both paracasein and casein combine with a number of acids to form unsaturated or mono-acid salts and saturated or di-acid salts. ‘‘ The unsaturated salts formed by casei’n and paracaseyn with acids are soluble in dilute solutions of sodium chloride and in 50 per cent. hot alcohol, but insoluble in water. The saturated salts are practically insoluble iu water, dilute salt solutions, and 50 per cent. hot alcohol. Both forms are sparingly soluble in dilute solutions of calcium lactate and calcium carbonate. ” The important changes taking place in the curd are considered due to the formation of the unsaturated paracasei‘n lactate, with which product the ripening process begins, and not with paracase‘in as has been universally held. “ T h e first step in the normal ripening process of American Cheddar cheese is probably a peptic digestion of unsaturated paracasein lactate.” H. W. LAWSON. Some of the Compounds Present in American Cheddar Cheese. BY I,. L.VANSLYKE ANI) E. B. HART. N. Y.State Agr. Expt. Sta. Bull. No. 2r9, pp. 203-216.--In studying the changes which take place in cheese during the ripening process, the authors found lysatine, histidine, and lysine in cheese four and one-half months old, and putrescine and lysine in cheese fifteen months old. Paranuclein was present in all the cheeses examined. The studies indicate that there is normally in the ripening of hard cheese a conversion of primary into secondary amido compounds, to which may be attributed the gradual development of flavor. T h e methods used in the separation of the different compounds are given. H. W. LAWSON. A llilk Unusually Rich in Solids. BY M, H. PINGREE.Pa. Agr. Expt. Sta. Rep., 1901,pp. ~gz-~gq.-’I’he milk of a healthy Guernsey cow four years old, and in her second lactation period, was found to contain on an average for two months, 5 . 8 per cent. of fat. Two samples taken about a month apart, soon after the
