598 EBPORT— 1881. 



The author has observed that re-solution of the phosphate of lime occurs when 

 the ammoniacal solution is heated with it in the water-hath, and that a clear viscid 

 solution is formed which, on cooling, solidifies and j-ields a solid, admitting of 

 being reduced to a fine powder. This double salt (which be believes is new) appears 

 to have the following formula : — 



P^OsCaOCNHJjOjH^O + aq. 



Excess of water breaks it up. Morfit has made the interesting observation 

 that when tribasic phosphate of lime (bone-earth) is dissolved in acid and then 

 reprecipitated with an alkali, it is reprecipitated in the form of hydi-ated tribasic 

 phosphate of lime. He has recenth' had an opportunity of confirming this observa- 

 tion on a very large scale, and the resulting hydi'ated tribasic phosphate is likely to 

 become of great importance in agi-iculture. 



4. 0)1 a New System of Blowpipe Analysis.^ ^y Lieut.- Colonel Ross. 



Among others, the following are points of novelty : — 



1. The use of aluminium plate for volatilising substances. 



2. A new air-reservoir mouth blo'n'pipe. 



3. A blowpipe or pyrological candle. 



4. Candle-scissors ; also used for general purposes. 



5. The use of watchmakers' pliers for holding, cleaning, and ringing platinum 

 wires. 



6. Agate slabs instead of the ordinar}- mortar for grinding powders, 



Heaffents. 



7. Boric acid (instead of borax). 



8. Phosphoric acid instead of microcosmic salt. 



Migcelloneotis Novelties. 



9. An- alloy button of gold and silver, in which these metals have been separated 

 by the blowpipe alone. 



10. A spectrum lorgnette, or spectracles, for observing blowpipe spectra while 

 you are producing them. 



11. A compass, in which the needle points E. and W., for ob\iating the 'dip' 

 in Arctic voyages. 



6. Oil Colliery Explosions. By "William Galloway. 



The author first described the genei-al arrangement of the airways and workings 

 in a large modern colliery, worked according to the long-wall method, and passed 

 on to notice some hypotheses which had been entertained by himself and others on 

 the causes of firedamp explosions. As regards that attributing an influence to 

 atmospheric pressure, it had been found by Mr. R. II. Scott and himself, that 

 whUe shallow mines are afiected by changes of weather, large and deep mines, in 

 which great explosions nearly always occm-, are not perceptibly affected by them. 



It had occurred to him that possibly a mixture of firedamp and air, which 

 contains too small a proportion of firedamp to render it explosive at ordinary 

 pressure and temperature, might become so when traversed by a wave of compres- 

 sion originated by a local fii-edamp explosion or by a blown-out shot. 



About the same time it occiu-red to him also, that the sound-wave originated 

 by a blown-out shot might carry the flame through the meshes of a safety-lamp 

 burning in an explosive mixtiu'e. Experiments had justified this hypothesis (see 

 ' Proc. Royal Soc.,' 1874). 



None of the foregoing hypotheses coidd account for all the phenomena observ- 

 able after a great explosion ; and, in pursuing the subject stiU fui-ther, he began, 

 towards the end of the year 1874, to specidate as to the probable influence of the 

 coal-dust which is to be found nearly everj-where on the floor of dry and dusty 

 mines. Further investigations led him to the conclusion that if a mixture of coal- 



' Detailed Paper published in the English Mecluinic and World of Science, of 

 September 30, 1881. 



