﻿318 Intelligence and Miscellaneous Articles. 



which is so small in comparison with the magnetism of the hydrates, 

 depends on an alteration in the density of the whole mass, or only 

 on an alteration of the magnetic atomic group itself. 



IX. The sulphur compounds corresponding to the salts of the mag- 

 netic metals investigated are, with the exception of sulphide of man- 

 ganese, very feebly magnetic. 



X. Nickel cyanide and cobalt cyanide have an atomic magnetism 

 which is only about 0'4 to 0*6 of the atomic magnetism of the other 

 salts of nickel and cobalt. When these cyanides are dissolved in solu- 

 tion of cyanide of potassium, their magnetism almost entirely disap- 

 pears. This cannot arise from the formation of a simple double 

 salt ; for the magnetic constituents in the double salts retain their 

 atomic magnetism unchanged ; the magnetic atomic group must 

 rather have itself changed. The salts formed have probably the 

 composition 2 KCy, CoCy 2 , and 2 KCy, NiCy 2 , corresponding to their 

 electrolytic deportment. The analogous magnetic deportment of 

 potassium ferrocyanide and potassium ferridcyanide favours this view. 

 From the experiments on the decomposition of magnetic salts by 

 double elective affinity, the potassium can be replaced by the magnetic 

 metals, which thereby retain their atomic magnetism unchanged as in 

 the ordinary oxygen and haloid salts. From the analogy with the 

 latter they would also have to be regarded as consisting of an equi- 

 valent of potassium combined in potassium ferrocyanide with a dia- 

 magnetic atomic group (Cy + |FeCy), by which the salt itself is dia- 

 magnetic, and in potassium ferridcyanide with a magnetic atomic 

 group (Cy + FeJCy), by the addition of which the salt becomes 

 magnetic. 



XI. The atomic magnetism of the three salts of manganese, iron, 

 and cobalt corresponding to potassium ferridcyanide is, both when in- 

 vestigated in the solid and in the liquid state, for one equivalent of 

 the magnetic metal (for instance Fe = 28, &c), — 



Potassium manganicyanide 145*4 



,. ferrocyanide 73*9 



,, cobalticyanide 3*5 



As in the oxygen and haloid salts of the three metals, the atomic 

 magnetism of potassium ferrocyanide is the mean between that of potas- 

 sium manganicyanide and potassium cobalticyanide ; and the three 

 atomic magnetisms of these salts are less by almost an equal amount 

 than the magnetisms of the oxide salts of the same metal, as if a 

 strong diamagnetic atomic group had been joined to the magnetic 

 metals in them. In the sulphocyanides the metal has the same 

 magnetic properties as in the simple salt of the same metal. — Ber- 

 liner Monatsberichte, July 1868. 



ON THE LATENT HEAT OF VOLATILIZATION OP SAL-AMMONIAC. 

 BY M. C. MARIGNAC. 



Sal-ammoniac when volatilized occupies double the volume re- 

 quired by a theory which of late years has had numerous partisans. 

 Is this to be ascribed to an anomaly in the physical constitution of 



