1873.] Technology. 553 



Struck with the inconveniences resulting from the use of toilet-soaps with a 

 base of potash or soda, M. Bonnamy has prepared alumina soaps. These are, 

 as a matter of course, neutral and free from causticity, and being insoluble in 

 water their detergent action is simply mechanical, not chemical. 



Ozokerit, which is now largely used in the manufacture of candles, is found 

 in beds in the sandstone of Slanik, in Moldavia, in the neighbourhood of 

 mines of coal and of rock-salt; it has also been discovered in the Carpathians. 

 The material in its crude state is brown, greenish, or yellow ; it is translucent 

 at the angles, and its fracture is resinous. It is naturally brittle, but when 

 softened can be kneaded like wax. It blackens on exposure to the air. It 

 becomes negatively electric on friction, and exhales then the aromatic odour of 

 a hydrocarbon. It melts at the low temperature of 66°. Its illuminating 

 power is such that 754 ozokerit candles give a light equal to 891 of paraffin, 

 or 1150 of wax. 



The recent sudden destruction of two large passenger ships, the Atlantic 

 and the City of Washington, has called attention to the desirability of availing 

 ourselves of the means which modern science has placed at our command for 

 the prevention of such disastrous accidents. For this purpose Mr. John 

 Newlands proposes that each large passenger ship should cany a small but 

 powerful steamboat or launch, and in foggy weather this steam launch should 

 be sent on ahead some few hundred yards, being connected with the passenger 

 ship by a flexible telegraphic cable provided with an electric battery, so that 

 signals or messages might be continually transmitted from one to the other. 

 The steam-launch should also carry an electric or other strong light, and be 

 provided with a powerful steam whistle. On meeting with ice or with vessels, 

 or unexpectedly approaching the coast, it would be comparatively easy to stop 

 the steam-launch and give warning in time to save the passenger ship from 

 danger. 



General Morin gives a formula indicating what amount of air should be 

 renewed hourly for each individual, in order that carbonic acid and vapours 

 exhaled may not accumulate beyond a proportion of o - ooo8 in a given enclosed 

 space. He finds that in a cubic space of 10 cubic metres this renewal hourly 

 should be go cubic metres; in 12, 88; in 16, 84; in 20, 80; in 30,70; in 

 40, 60 ; in 50, 50 ; in 60, 40. Various applications of the formula are sug- 

 gested — barracks, bedrooms, public halls, hospitals, &c. 



Some improvements in photo-lithography have been effected by M. Paul. The 

 paper is coated with a layer of white of egg beaten up and mixed with a con- 

 centrated solution of bichromate. When dry it leaves a hard smooth surface. 

 After a sufficient insolation under the negative, the paper is covered with 

 lithographic ink, then immersed in cold water to dissolve out the unchanged 

 albumen, which is then removed with a fine sponge. 



Horsky's diffusion apparatus does away with the rasping process in the manu- 

 facture of beet root sugar, dispenses with three-fourths of the manual labour, 

 and extracts the saccharine matter completely. The yield of sugar obtained 

 by the use of this arrangement has this season amounted to 8*5 per cent, an 

 amount greatly superior to that obtained in establishments where other pro- 

 cesses for extraction are in use. 



The following is the formula for Dr. Jeannel's horticultural manure : — 



Nitrate of ammonia 400 parts. 



Biphosphate of ammonia .. .. 300 ,, 



Nitrate of potash 250 „ 



Hydrochlorate of ammonia . . . . 50 ,, 



Sulphate of lime 60 ,, 



Sulphate of iron 40 ,, 



At a general meeting of the Societe Francaise de Photographic held on 

 August 1, 1873, a letter from M. Anthony, of New York, was read, offering 

 the following prizes, open to photographers of all nations : — 100 dols. for the 

 best bust of a lady ; 100 dols. for the best head of a boy under six years of age ; 

 100 dols. for the best head of a girl under six years of age ; 100 dols. for the 



