354 THE CANADIAN NATURALIST. [Vol. viii. 



1. In basaltic (crystalline) 

 hornblende from porphyritic 



basalt from Liebhards (Rhone) Cu not determinable. 



Co very evident. 



2. In the hornblendic schists 



from Goldbach near Aschaffenburg Copper and cobalt. 



3. Ditto from Oberkotzan near Hof Cu faint, Co evident. 



4. Ditto from Albbruck near 



Waldshut (Baden) No Cu, no Co, only Mb. 



5. Ditto from Webicht, near 



Schmalkalden No Cu, Co very evident. 



6. Ditto from Johanngeorgen- 



stadt in the Erzgebirg Cu comparatively much, 



Co less, but very ev ident. 



7. Dark-black hornblende with 

 olive-green streak from Pracken- 



dorf in Hungary Cu and Co very evident. 



Up to this time cobalt had been observed in no hornblende, and 

 copper only in the actinolite of Reichenstein (0.40 per cent., Rich. 

 ter) and in the Smaragdite of Corsica (1.5 per cent., Vauquelin). 

 Whereas copper and cobalt in consequence of the intense borax 

 beads that they give before the blowpipe can be easily and surely 

 discovered, even in a very small quantity of the hornblendes that 

 have been so far examined ; nickel could but very seldom be dis- 

 covered accompanying the cobalt, as it usually occurs in still 

 smaller quantity.* Whilst in the olivine of Neurod, the ratio of 

 Ni : Co. was about as 51 : 1, it might probably be reversed in 

 many hornblendes. But considerably larger quantities than 

 hitherto must be operated upon, in order to separate the nickel, 

 when it occurs, from the cobalt, and determine it with cer- 

 tainty. I have not yet examined the hornblendes for bismuth 

 and arsenic. That the latter occurs in hornblendic schists I 

 doubt so much the less from having found it to my very great 

 surprise so long ago as 1862, in its native form, in the quartz 

 stringers of the rock near Maisach, not far from Oppenau. 

 Whenever a violent decomposition of the hornblendic schists 

 occurs, which, however, has but seldom been observed, smaltine 



* Certain Scandinavian hornblendic rocks behave evidently quite 

 otherwise in this respect, since they contain highly nickeliferous 

 magnetic pyrites and iron-nickel pyrites. 



