56 Scientific Intelligence. 



are black in thick but dark red in thin layers, become blued like 

 steel when heated in the air though not con, 

 in a stream of oxygen. Their hardness is between 9 an 

 density 2-5345. Concentrated hot nitric and dusohts them 

 slowly, fused potash and lead chromate rapidly On analysis 

 they yielded 17-30 per cent of aluminum and 82-70 per cent of 

 boron corresponding to the formula A1B, .. The yellow quadratic 

 crystals were obtained by effecting the fusion in carbon crucibles ; 

 one melting, which was on a large scale, yielding 5-528 orams 

 pure crystals, on some of which the octahedral edges were I mm 

 long. They are honey-yellow in color, very brittle, harder than 

 corundum and nearly as „ 111( j an( j nave a density 



of 2615. On analysis they gave as a m. . 



iron 0-24, copper 0-04, carbon !VIlee ) 82-81:' 



corresponding to the formula C, A1 3 B 4 8 . All attempts to prepare 

 pure boron crystallized were fruitless. ' The author is now exam- 

 ining the so-called amorphous boron in this direct inn. _/,;, i.;,,- 8 

 Annalen, clxxxiii, 75, Oct., 1876. G p b 



2. On the Constitution of the Phosphates.— Berthelot and 

 Lottguinine have made a thermic research ..,, ,.1,.....;,. „ i,- . ,-i . 1 

 with a view to determine its hasiritv. Thev studied the heat- 

 changes characterizing the union of this acid with two widely 

 different bases, ammonia and baryta, and those produced by 

 water and by various acids of different energy upon the three 

 classes of phosphates. To these, they added alkalimetrical 

 evidence. The conclusion which they reach is that the three 

 equivalents of base, successively united to phosphoric 

 thus united with very ;ilent b ' ei 



comparable to that of the nitrates or alkali chlorides, the second 

 to that of the carbonates and bor I to that of 



the alkali alcoholates. When for example, phosphoric acid and 

 soda unite, the union of the first equivalent of the base evolves 

 14-, calories, the second 11-6 calories and ti 

 while in the case of a true tribasic 



heat is constant for each equivalent, being in this case 12-7 

 se of ammonia, no heat at all is evolved on 

 adding the third equivalent, and hence no triammonium phosphate 

 exists In view of the results obtained, the authors say that 

 phosphoric acid cannot be a tribasic acid, at least in tin" --,„„■ 

 sense as citric acid, the third equi , separated 



even by dilution; nor can it be 



oxalic or tartaric acid, since the second equivalent of base is not 

 i by the acid and is em; hydrochloric 



and nitric a. m • .ally by acetic. Hence they regard 



it as an exam , ; 1( . | MD> 



istry are called monobasic acids with a mixed function.— Ann. 

 lh,m. /%«., V, ix, 33, Sept., 1876. ,, F B 



, 3 - ° nthe ' ■'/ " id Carbon Dioxide— -Hartley 



has made further examinations of the liquid enclosures in minerals 



and has determined with care the critical poi 



temperatu 



