250 



SCIENCE. 



[N. S. Vol. XX. No. 503. 



eration of silicon hydrids. These with the 

 air in the drums formed an explosive mixture, 

 which could be readily ignited by the friction 

 between the lumps of ferrosilicon, or possibly 

 by the presence of a phosphin which was spon- 

 taneously inflammable. Although these par- 

 ticular explosions were not very serious, the 

 authors feel that attention should be called to 

 the possibility of accidents of this kind in 

 storing and shipping ferrosilicon, and make 

 the suggestion that care should be taken that 

 it always be kept dry and in a place where it 

 will be well ventilated, thereby insuring 

 against the possible accumulation of inflam- 

 mable gases. 



BESSEMER VS. OPEN-HEARTH. 



At the same meeting Mr. F. J. E. Carulla 

 made an appeal for the preservation of the 

 Bessemer steel- industry. He described the 

 manufacture of Bessemer rails in 1874 and 

 held that the uniformity of the product then 

 obtained left nothing to be desired. These 

 requirements could and should be equally well 

 fulfilled at the present day, and improvements 

 should be made in the modern Bessemer proc- 

 ess to enable this. This process ought not to 

 be completely relegated to the rear by the de- 

 velopment of the open-hearth furnace. 



ROYAL SOCIETY CONVERSAZIONES. 



The two conversaziones of the Royal So- 

 ciety held this year in May and June con- 

 tained, from the descriptions in Nature, less 

 than usual of interest to chemists. Naturally 

 there were several exhibits in connection with 

 radioactivity, the most interesting being an 

 apparatus showing the spontaneous electrifica- 

 tion of radimn by Hon. E. J. Strutt. The 

 radium salt in a glass tube is hung by an in- 

 sulating support in an exhausted vessel. An 

 electroscope is attached to the radium tube. 

 Negatively electrified particles from the 

 radium penetrate the glass tube which is cov- 

 ered with a conducting coating of phosphoric 

 acid, so as to act as an inductor. Thus a 

 positive charge is left and causes divergence. 

 When the electroscope leaf touches the outer 

 vessel, which is grounded, it collapses, and 

 then begins to charge up again. This action 

 goes on as long as the radium lasts. 



Dr. Alan B. Green exhibited photographs 

 illustrative of induced radioactivity of bac- 

 teria. Small masses of bacterial growth were 

 exposed to the ^ and y rays of radium bromid. 

 Many of these masses when removed from the 

 influence of the radium and placed between 

 two thin plates of glass, were capable of affect- 

 ing the photographic plate, even through a 

 double layer of lead foil. 



Mr. William Burton and Mr. Joseph Burton 

 exhibited specimens of newly discovered crys- 

 talline glazes developed on English earthen 

 and stoneware. These are artificial crystal- 

 line silicates, formed during the firing and 

 cooling of the wares. In the ' sunstone ' and 

 ' fiery ' glazes, the crystals show the optical 

 properties of micas, in the starry and opal- 

 escent glazes the radiating needles are akin to 

 the mineral willemite, as is shown both by 

 their optical properties and chemical composi- 

 tion. The writer recalls that a year ago an 

 American potter showed him a number of tiles 

 with glazes similar to these last, with which 

 he was then experimenting, hoping to produce 

 them upon wares. They were remarkably 

 beautiful, but it is not known whether they 

 have yet been produced commercially, either 

 in this country or in England. 



NATURE OF SOLUTIONS. 



Two important papers on solutions have re- 

 cently appeared from Lobry de Bruyn in the 

 Recueil des Travaux Chimiques des Pays- 

 Bas. The first, in collaboration with L. K. 

 Wolff, is on the possibility of detecting the 

 presence of molecules in solutions by Tyndall's 

 optical method. Spring has devised the 

 method of rendering liquids optically clear, 

 that is, showing no trace of a strong ray of 

 light directed through them, by producing in 

 them a precipitate of a colloidal hydroxid. 

 This precipitate on settling carries down with 

 it every solid particle which may have been 

 suspended in the liquid. It was noted, how- 

 ever, by Spring that solutions of certain salts 

 like alum and ferric chlorid could not be 

 made optically clear and this was attributed to 

 the formation of basic salts by hydrolytic dis- 

 sociation. These basic salts form solid par- 

 ticles of ultra-microscopic size, which never- 



