July 23, 1908] 



NA TURE 



275 



tons per kilowatt year, and two tons of carbide will 

 absorb practically 500 kilograms of nitrogen in the 

 form of nitrolim. A power of about 25 h.p. is re- 

 quired per year for fixing each Ion of nitrogen, and 

 in addition' to this about one-third horse-power is 

 required for the grinding and all other mechanical 

 operations. Consequently, to produce suflicient nitro- 

 lim to take the place of all the Chili saltpetre at 

 present consumed annually, plant developing no less 

 than 800,000 h.p. would be required. Not only is 

 nitrolim useful as a fertiliser, but quite a large variety 

 of chemical products have been made by means of it. 

 For instance, by melting it with a flu.-v, a mixture 

 containing 25 per cent, of potassium cyanide, which 

 is found to work quite as efficiently for the extraction 

 of gold and silver as the pure product, is produced. 

 It comes on the market under the name of " Surro- 

 gate." Ammonia may be produced very readily from 

 this product, and may be collected pure or used for 

 making salts of ammonia. (Fig. 3 shows diagram- 

 m.atically the form of plant employed.) Another pro- 



at least 50,000 h.p., is being erected at .\IiTiissa. 'n 

 France the Sociefe Francaise des Produits Azotes 

 has installed works at Notre Dame de Briangon 

 (Haute Savoie) having an output of 4000 tons, and 

 these have been in operation for about six months. 

 In Germany, at Westeregeln and Briihl, on the 

 Rhine, 10,000 tons of nitrolim are being annually 

 manufactured. It should be noticed, however, that 

 the works at Briihl do not employ water power, but 

 as the coal in this district is cheap, it is used in 

 place of water power. In the United States the 

 .American Cyanamide Compan}' are constructing 

 works on the Canadian side of the Niagara Falls, with 

 a capacity of from five to six thousand tons per 

 annum, which it is hoped to enlarge later on so as to 

 produce 40,000 tons. 



The chief British enterprise is the North-Western 

 Cyanamide Company, Ltd., which has erected works 

 at Odda. Figs. 4 and 5 show the Isere Valley, 

 Notre Dame de Brian^on, and the main building's of 

 the cyanamide works. Fig. 6 shows the Linde 

 machinery employed there for frac- 

 tional distillation of the air. 



F. M. P. 



Fig. 6. — Linde Machinery. 



duct is dicyandiamide, which is being used in increas- 

 ing quantities for the manufacture of organic dyes. 

 Besides which there are urea, thiourea, ferricyanide, 

 and a variety of other products. 



.\s a commentary upon the Birkeland-Eyde process 

 worked at Notodden, it is of interest to notice that 

 the Cyanamide Company at Odda fix about the same 

 quantity of nitrogen as the Birkeland-Eyde; but 

 whereas the former employed about 25,000 kilowatts 

 of power, the energy required by the latter company 

 is between five and six thousand kilowatts. It would 

 thus appear that the actual fixation is cheaper in the 

 form of cyanamide than in that of calcium nitrate. 

 At the end of the present year it is hoped that works 

 having a total output of 45,000 tons of nitrogen will 

 be in operation, and in the course of next year a 

 correspondingly large increase in production of this 

 product is predicted. It should be mentioned that 

 the first plant upon an industrial scale was started 

 about two and a half years ago, at Piano d'Orta, in 

 Central Italy, with a yearly production of about 4000 

 tons of nitrolim. These works are now being in- 

 creased to a capacity of 10,000 tons. Other im- 

 portant works are being started in Italy; the power 

 employed is hydro-electric. 



Works are being erected in Austria-Hungary, and 

 at the nresent time a water-power installation, giving 



NO- 2021, VOL. 78] 



TH£ EDUCATION OF THE 

 BLIND.' 



'T'HE jubilee year of the Insti- 

 ■* tution for the Blind at 

 Illzach-Mulhausen has been cele- 

 brated by the publication of a 

 " Festschrift," which contains ad- 

 dresses and papers by Prof. Kunz 

 and others at the congresses re 

 garding the blind held in Frank- 

 fort in 1882, .Amsterdam, 1885, 

 Kiel, 1891, Berlin, 1898, Paris, 

 1900, Breslau, 190 1, Halle, 1904, 

 Leipzig, 1905, and in Rome, 1906. 

 There is first an interesting 

 account of the development of the 

 Institution at lUzach since its 

 foundation in 1856. Institutions 

 for the blind were founded in 

 various cities long before this date. 

 Thus, to select from a long list of 

 the chief cities of the world, we find one in Paris in 

 1784, in Liverpool (the first English institution), 1791, 

 Edinburgh, 1793, London, 1799, Berlin, 1S06, St. 

 Petersburg, 1807, Stockholm, 1808, Dublin, i8io, 

 Barcelona, 1820, Munich, 1S26, New York, 183 1, 

 Bern", 1836, Padua, 183S, and Madrid, 1842. 



The home at lUzach was at first small and modest, 

 but it grew rapidly, and now it is one of the best 

 equipped blind asylums. From the first its founders 

 had in view that it w-as not merely to be a 

 home for the blind, but a school in which all the 

 eletnents of an ordinary education, and also of a 

 technical education, could be taught. Nothing is more 

 ingenious than the methods now adopted for the edu- 

 cation of the blind, more especially by the sense of 

 touch. Reading by raised type, or by a system of 

 raised points so grouped as to represent numerals or 

 letters, arithmetic, grammar, geometry, geography by 

 raised maps, natural history by specimens of plants 

 and animals or by anatomical models, or the outlines 

 of plant and animal forms in bas-relief, music — theo- 

 retical, vocal, and instrumental — and gymnastics, and 

 many technical arts are also taught, such as sewing, 



1 Gescllichte der Elindenanstalt zu Illzach -Miilhausen i E. Walirend 

 der ersten fiinfzig Jahre ihrer Tatigkeit. ferner deutsche, franzosische, und 

 italienische Kongressvortrage und Abhandlungen iiber das Blindenwesen, 

 Prof. M. Kunz, Direktor der .-instalt, 1S56-1906. Pp. 146 ■ 'Leipzig : 

 Wilhelm Engelmann, 1907.) 



