Fbbkuaey 18, 1898.] 



SCIENCE. 



237 



NOTES ON INORGANIC CHEMISTRY. 

 Geoege Merer, in a recent Comptes 

 Eendus, calls attention to the fact that, 

 while fused sulfate of ammoniuni or the 

 alkaline halids have little or no effect on 

 platinum, a mixture of ammonium sulfate 

 and bromid or potassium bromid corrodes 

 the metal very rapidly. Platinum black 

 or even finely divided metallic platinum, is 

 rapidly brought into combination with this 

 mixture at 330°, the bromo-platinate of 

 ammonium being formed. The other met- 

 als of the platinum group have not been 

 tested with this mixture by the author. 



It is many years since Dr. Kiinzel called 

 attention to the fact that in a nickel solu- 

 tion containing potassium nitrite even 

 traces of a calcium salt give a yellow pre- 

 cipitate. Several of these triple nitrites 

 have been from time to time studied, and 

 in the last Zeitsehrift fur anorganisehe Chemie 

 Carl Przibj'Ua gives a systematic study of 

 these salts. CuBa K^ (NOJ^ may be taken 

 as a type of the triple nitrites. The copper 

 may be replaced by nickel or iron, the 

 barium by calcium, strontium or lead, and 

 the potassium by ammonium. The salts 

 are very insoluble, not stable in the 

 presence of water, and some of them appear 

 to be mixtures, but even these mixtures 

 closely approximate the above formula. 



The work of Melikoff and Pissarjewsky 

 on peruranic acid was recently noticed in 

 this column. According to their view of the 

 constitution of this acid, its ammonium 

 salt should contain ammonium peroxid, and 

 their efforts to obtain this compound are the 

 subject of a preliminary communication in 

 the last Berichte. By mixing concentrated 

 ether solutions of hydrogen peroxid and 

 ammonia at — 20°, a thick liquid was ob- 

 tained which had little odor of ammonia, 

 and which, on further cooling with liquid 

 carbon dioxid, crystallized. Analysis of 

 tte crystals gave the composition (N H^)^ 



O^ , 2 H,0, , 10 H ,0. The water of crys- 

 tallization seems not to be constant, but the 

 existence of the peroxid of ammonium of 

 the formula (N HJ^ O^ , 2 H„ O^ appears 

 well established. 



J. L. H. 



SCIENTIFIC NOTES AND NEWS. 



THE TOTAL ECLIPSE OF THE SUN.* 



The observation of the total solar eclipse in 

 India has been a magnificent success. Here at 

 Taini, during the three weeks of our prepara- 

 tions, we never saw a single cloud and to-day 

 has been as perfect as those which have pre- 

 ceded it, and whilst we are rejoicing over our 

 own good fortune the news is flashed to us that 

 at Buxar, in the east, and Jewar, in the west, 

 observers have been equally favored. Thanks 

 to the forethought of our host, Lieutenant Mor- 

 ris, no spectators were allowed to approach 

 within several hundred yards of our camp, and 

 we observed the superb spectacle free from the 

 slightest interruption. The first encroachment 

 of the dark body of the moon gave us an hour 

 and a half's warning of totality, and slowly in- 

 deed did the first part of that time pass. A fine 

 procession of sharply-defined spots lay across 

 the solar disc, and were swallowed up one by 

 one by the invading darkness. The air, which 

 had been intensely hot, grew chill, the weird 

 sense of approaching disaster which always ac- 

 companies an eclipse oppressed the nerves, and 

 then, with what seemed a sudden rush, the 

 shadow fell. 



I was watching the eclipse through a binocu- 

 lar, one lens of which was fitted with an 

 eyepiece prism. As totality approached the 

 burning spectrum at the sun became crowned 

 with dark semicircles — the Fraunhofer lines. 

 These grew finer and sharper, and then sud- 

 denly turned to bright flame at either end of 

 the semicircles. The continuous spectrum nar- 

 rowed, the bright arch grew with startling swift- 

 ness, a long constellation of glittering points 

 sparkled out for a fraction of a second, and 

 totality had begun. 'Go!' I cried. The sig- 

 nal clock was started, and its clear beat rang 

 out, emphasized at every tenth second by the 



* A cablegram to the London Times. 



