T H E JOGRNAL OF I,\TDUSTRId.L
46 2
i t consisted of rubber composition with insertions of duck or sheeting, and was used between 1860 and 1875, when the steam pressure did not exceed 80 pounds per square inch. Afterwards came plumbago and rubber compositions, termed “self-vulcanizing” packings; these were found to be more durable and satisfactory under the conditions then existing than the preceding, but had the disadvantage that they had to be baked into the joint. In 1886, several semi-vulcanized rubber-composition packings appeared on the market, and a composition of rubber and asphaltum, suitable for liquid conditions, was next introduced. During the period 1900 to 1910, steam pressures have increased from 80 to zoo pounds and over in stationary plants. This increase brought a corresponding rise in temperature, which was further increased by the practice of superheating. Then, too, the wider use of the air compressor, ice machines, gas engine, superheater, etc., created extreme temperatures demanding a packing which could meet exacting conditions. It is said that composition packings have been perfected which possess great resistance to extreme heat as generated under high pressure. The basis of the material is pure asbestos fiber, the fibers being treated with a waterproof compound to prevent the absorption of water. The treated fibers are compressed into sheets, pliable, resilient, and of high tensile strength. DEVELOPMENTS I N STEAM GENERATION. I n the United States the employment of measuring instruments in the boiler room has rendered it possible to make the boiler conform more closely to the load curve than formerly. H. G. Stott points out in the Electric Railway Journal, 38, 781, that the Venturi meter for measuring the feed to the individual boiler; the Pitot tube in the steam pipe for giving a general indication of the relative amount of work done in different boilers; and a coal-measuring instrument in the chute or downtake coal pipe, have been used along with forced combustion. He studied the records of one-minute indications of steam and water-flow meters to show the variations in power due to variations in load. To meet these variations, it is recommended that the boiler room should be designed for maximum operating conditions and economy a t average load, and to sacrifice slight economy a t light loads by working only one of a pair of grates t o each boiler, the other being banked; or to employ the auxiliary use of liquid fuel; or to have grates capable of working with natural draught up to a given power and thereafter with forced draught. THE CONTACT PROCESS OF SULPHURIC ACID MANUFACTURE. Wieland [Ber., 45, 685 ( I ~ I ? ) has ] studied the catalytic conversion of sulphur dioxide into sulphuric acid. When palladium black is exposed to moist sulphur dioxide, air being excluded, and the excess of sulphur dioxide is afterwards removed by carbon dioxide, sulphuric acid is found in the palladium, which can only have resulted by the removal of hydrogen from sulphurous acid‘ H$O, = H , t SO,; SO, t H,O = H,SO, The equivalent hydrogen was not found, but, instead of it, sulphur; and Wieland has found that palladium-hydrogen does reduce aqueous sulphurous acid: SO, -t zH, = zH,O S He therefore suggests that the ordinary contact-process of sulphuric acid manufacture is not a direct oxidation, but a reaction similar to the above, in which the function of the oxygen is to oxidize the hydrogen produced, forming the water which is itself necessary for the reaction to occur: SO, H,O = H,SO, = SO, H2;2H2 0, = zH,O
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A,‘\-D E-YGI-\-EERI-YG C H E X I S T R Y .
June, 1912
FORTOLINE.
In 1910, K. Hadorff (French Patent 416,325, April
27,
1910)
devised a fuel “for increasing the poxer of internal-combustion engines,” consisting of “benzene picrate” (prepared by dissolving picric acid in benzene, heating for a prolonged period, and finally separating the excess of benzene by distillation) mixed with benzene or other liquid hydrocarbon. This fuel was said to burn without the formation of any deposit in the cylinder. The fuel claimed in First Addition, d+ted September 2 j , 1911, to French Patent 416,32j , termed “Fortoline,” contains nitrobenzene in addition to “benzene picrate;” I O parts of benzene are mixed with 0.5 part of nitrobenzene to which a small quantity of picric acid has been added, and the resulting mixture is boiled for a long time. The product is added to IO times its amount of petroleum, naphtha, petrol, benzene, or other hydrocarbon, and is claimed to “increase the power of internal-combustion engines” when the treated fuel is used therein. THE UTILIZATION OF STORAGE BATTERYiSLUDGE. The sludge of lead peroxide and sulphate which accumulates during long periods in lead batteries has a value on account of its lead content, but its transportation to lead smelteries has been expensive and difficult because of the associated acid. Moreover, washing and pressing are out of the question because of the fine state of division of the lead peroxide. In German Patent 236,343, it is claimed that these difficulties are overcome by mixing the sludge with slaked lime; the mixture quickly sets to a firm cake. An alternative plan is to mix the sludge with the sulphite liquor from sulphite cellulose works, the lead peroxide being thus converted into lead sulphate; molasses may also be employed for the reduction of the peroxide. So much heat is liberated during these reactions that considerable of the water is evaporated. THE MANUFACTURE OF WHITE LEAD. It is reported (Chem. Trade I,, 50, 386) that the West German Lead Color Works are now in the possession of a new process for manufacturing white lead which does away with the difficulties of dissolving the lead, encountered in the old Dutch process. Finely divided lead (readily obtainable now in a uniform state) is put into a chamber, acetic acid is added, and air is led through for agitation: a large amount of lead becomes soluble. The lead solution is then subjected to the action of carbon dioxide under pressure in another chamber, and the lead lye and white lead formed are removed by atmospheric pressure. The method can be worked in a few hours instead of weeks, and, furthermore, no lead residues are left and less acid is used. In German Patent 244, jog, recently issued, a novel process of making white lead is claimed. Litharge is treated with a boiling solution of amino acids, such as result upon the hydrolysis of albuminoid substances, and the lead is precipitated by: a current of carbon dioxide. Since the organic acids remain in solution, the liquor can be used continuously for dissolving more litharge. THE PURITY O F COMMERCIAL METALS. Mylius (2. anorg. Chem , 74, 407) suggests that instead of the existing irregular nomenclature (“pure,” “puriss.,” etc.) for denoting the purity of commercial metals, a system of numerical classification be employed. According t o this plan, the first degree of purity would represent a metal in vhich the total true impurity, with the exception of oxygen and the products of atmospheric corrosion, was from 1-10 per cent.; the second
