Over 3,000 teachers' positions are said to be vacant at the present time. * * * * * BLEACHING SILK AND WOOL. The methods now in use for bleaching silk, wool, and all animal fibers, such as sulphurous acid, alkalies, soap, etc., are so imperfect that Tessié du Motay has patented the following process, involving the use of binoxide of barium, with or without the addition of permanganates. The binoxide of barium is pulverized and subjected to the action of carbonic acid to remove any unconverted caustic baryta present. It is then thrown into boiling water, and after the bath has partially cooled the materials to be bleached are introduced and the bath kept at a temperature of 86° Fah. to 194° Fah. for two hours; silk from wild silkworms requiring a higher temperature than wool, goat's hair, and the like. It is then taken out and washed, put into an acid bath, then washed again. If necessary, the barium bath is repeated, as also the subsequent washings. If this second bath of binoxide of barium does not produce the requisite whiteness, it is introduced into a solution of permanganic acid or permanganate of magnesia before the last washing. Binoxide of Barium, BaO_{2}, is made by subjecting the oxide or caustic baryta, BaO, to a stream of oxygen or common air at a high temperature. Its bleaching action is probably due to the formation of peroxide of hydrogen in solution in the bath. * * * * * AN ALLOY OF TIN AND PHOSPHORUS. At the Graupen Tin Works, in Bohemia, an alloy of tin and phosphorus is made containing the greatest possible quantity of phosphorus which the tin is able to retain without losing any of it upon repeated meltings. This compound, which is neither entitled to the name of alloy nor is it a phosphide of tin, is employed in the manufacture of phosphorus-bronze. In the manufacture of phosphorus-bronze, by alloying copper with phosphorus-tin, no other precautions require to be observed than in the preparation of common bronze. As the different properties of phosphorus-bronze depend upon the proportions of phosphorus and of tin, two kinds of phosphorus-tin are prepared. No. 0 contains 5 per cent., and No. 1, 2½ per cent. of phosphorus. These two kinds suffice to make the greater part of all the desired mixtures. For special purposes, the Graupen Works make to order phosphorus-tin with any desired quantity of phosphorus not exceeding 5 per cent., which is the highest possible limit. It is claimed that phosphorus-bronze may be manufactured by the use of this phosphorus-tin as much as 40 per cent. cheaper than that now in the market, while it will only cost 8 per cent. more than the ordinary tin and copper bronze. No details are given of the method employed to make the phosphorus combine with tin, but the low melting point of tin as compared with that of copper would indicate that this would lead to the great saving promised above.