1873.] Technology. 551 



with the outer tube, and is completely coated on its exterior surface with tin, 

 the tin being acted on to the smallest extent by the ozone. This hollow box 

 communicates with the exterior of the apparatus by means of tubes passing 

 through the centre of the caps. It is intended that a current of water should 

 circulate through this box. In the small annular space between the box and 

 the glass tube oxygen is passed from the tubes fitted to the cap. The box 

 itself forms one of the electrodes in connection with an induction coil, and a 

 strip of tin-foil fixed to the outside of the glass tube forms the other. 



Another interesting but different order of experiment, a discovery of 

 M. Demoget, consists in replacing the plate of resin of an electrophorus by a 

 membrane of caoutchouc. The membrane from a child's air-balloon strained 

 on a metallic circle of O'S cm. diameter, smartly rubbed with the back of the 

 hand, the rubbed surface inverted upon a good conductor and the superior 

 surface rubbed, will result in imparting to an insulated disc of 25 cm. diameter 

 sufficient electricity to discharge sparks of 3 to 5 cm. length. The experiment 

 may be utilised in the charging of an electrometer, or may be the source of 

 amusement to the young. 



The electrical theories advanced by M. Edlund, and that of electrolysis by 

 M. Domalip, during the last quarter, would require more space for adequate 

 consideration than can be afforded to a resume. 



M. Dupuy de Lome describes the cryptograph of M. Pelegrin as an instru- 

 ment' designed to be raised on the ground, and to convert into expressions 

 capable of being transmitted directly and secretly by telegraph, the polar co- 

 ordinates of points which determine a given figure ; whence the possibility 

 with this instrument of following and interpreting, that is, of drawing, in 

 Paris, e.g., what correspondents in different parts of the country in telegraphic 

 communication with Paris may see and telegraph but do not interpret. 



TECHNOLOGY, &c 



In consequence of the illness of Dr. Joule, Dr. A. W. Williamson, F.R.S., 

 presided over the Bradford Meeting of the British Association for the Advance- 

 ment of Science. His Inaugural Address, which attracted the deepest atten- 

 tion, was delivered on the evening of the 19th of September. Owing to the 

 meeting being held later in the season than usual we are prevented from giving 

 an abstract of the proceedings in our present number. Evening lectures were 

 delivered by Prof. W. C. Williamson, on "Coal and Coal-Plants; 1 ' by Dr. 

 Siemens, F.R.S., on "Fuel;" and by Prof. Clerk Maxwell, F.R.S., on 

 " Molecules." Dr. Russell, F.R.S., was President of the Chemical Section. 

 He departed from the usual custom of reviewing the progress of chemistry 

 during the year; and after a feeling allusion to the death of Liebig, and to his 

 connection with the British Association, the attention of the audience was 

 directed to the history of the colouring matter found in madder. Of the 

 papers read before the Association, that which deservedly attracted the greatest 

 attention was Dr. Ferrier's paper on the " Brain." We shall give an authentic 

 account of these important researches in our next number. 



The American Association for the Advancement of Science held its twenty- 

 second annual meeting at Portland, Maine, beginning Wednesday, August 20th. 

 The Officers of the meeting were — President, Prof. Joseph Lovering, of Cam- 

 bridge, Mass.; Vice-President, A. H. Worthen ; Permanent Secretary, F. W. 

 Putnam ; General Secretary, C. A. White. The attendance of members was 

 large, and a goodly number of papers were presented. The following papers 

 on chemical and closely related subjects were read : — " On the Silt Analysis 

 of Soils and Clays," E. W. Hilgard ; " Analysis of Mississippi Soils and Sub- 

 soils." E. W. Hilgard ; " On the Distribution of Soil Ingredients in the Sedi- 

 ments obtained by Silt Analysis," R. H. Loughbridge ; " On the Influence of 

 Strength of Acid, and Time of Action on the Results of Chemical Soil 

 Analysis," R. H. Loughbridge ; " Remarks on Plate Lime-Glass and the 

 Manufacture of Glass in General," L. Feuchtwanger ; "The Chemistry of 

 Copper Matte," T. Sterry Hunt ; " Metaphysical Theory of Chemistry versus 



