Chemistry and Physics. 391 



SCIENTIFIC INTELLIGENCE. 



I. Chemistry and Physics. 



1. Investigations with sulphide of nitrogen. — In a preliminary 

 notice, Clever and Mfthmann have described a few products 

 obtained by the action of several reagents upon this well-known 

 explosive compound. The substances obtained are so remarkable 

 in composition and behavior that it is evident that the authors 

 have opened up an important field of investigation. By deter- 

 mining the elevation in boiling-point of the carbon disulphide 

 solution, the authors have confirmed the recent results of Schenek, 

 who used the depression of the freezing-point in naphthalene solu- 

 tion, in arriving at a molecular weight 184 for sulphide of nitro- 

 gen, corresponding to the formula N 4 S 4 . By the action of an 

 excess of bromine upon a solution of nitrogen sulphide in carbon 

 disulphide, a well crystallized, bronze-colored compound, N 4 S 4 Br 4 , 

 was obtained. By exposure to the air, the substance just men- 

 tioned loses sulphur bromide by evaporation and is changed into 

 a yellow amorphous compound, probably having the composition 

 N 4 S 6 Br 2 . If bromine vapor is allowed to act upon dry nitrogen 

 sulphide, it is greedily absorbed, liquefaction takes place and 

 after some time large garnet-red crystals of a very unstable body 

 with the composition NjS 4 Br 6 are formed. By exposure to the 

 air this substance yields the previously-mentioned yellow amorph- 

 ous body. The most interesting compounds, however, are those 

 which will be now mentioned. By the action of nitrogen dioxide 

 (N0 2 ) upon a solution of nitrogen sulphide in carbon disulphide, 

 a very deliquescent, white crystalline compound, probably NS0 4 , 

 is produced. It reacts with water with the evolution of NO and 

 the formation of sulphuric acid, probably according to the equa- 

 tion, 



NS0 4 + H 2 = NO + H 2 S0 4 . 



Upon acting upon the previously-mentioned substance, N 4 S 4 Br 4 , 

 while suspended in carbon disulphide, with nitrogen dioxide, a 

 canary-yellow, substance is deposited in microscopic crystals. 

 This is free from bromine and probably has the composition rep- 

 resented either by the formula NSO or N B S 6 4 . This compound 

 decomposes suddenly, giving forth a brilliant light, even when a 

 tube containing it is exposed to the heat of the hand. It dis- 

 solves in water, giving a yellow, neutral solution, which, upon 

 warming, deposits a black substance. The latter quickly decom- 

 poses into sulphur and a gas of peculiar odor, which has not yet 

 been investigated, but , which the authors surmise to be a lower 

 oxide of sulphur. The canary yellow compound behaves in a 

 different manner with alcohol, giving a dark red solution which 

 gives off sulphur dioxide upon boiling and deposits a crystalline 

 substance which had not yet been analyzed. Another curious 



