Mr. T. Hemy on the White Blende of New Jersey, U.S. 23 



face of the water. Hence, in the case of the water-bellows, it is 

 unnecessary that the tubes AA, fig. 13, should reach under the 

 surface of the water in the drum CC. 



These experiments show that a similar action takes place here 

 to that which we have so often an opportunity of observing when 

 a fluid is poured into a glass, in which case also bubbles are 

 carried downwards. This action has however been sufficiently 

 explained in § 18 to § 20 ; and I introduce the water-bellows 

 here merely to show its intimate connexion with the results 

 already described. 



II. On the White Blende of Netv Jersey, U.S. 

 By T. H. Henry, Esq., F.R.S.'^ 



AVERY transparent coloui-less mineral, called white blende, 

 occurs at Franklin in New Jersey, U.S. Mr. Nuttall, 

 who supposed it to differ from common blende, has named it 

 " Cleiophane," and some other authority has called it Cramerite; 

 but although it is the only instance of the occurrence of colour- 

 less blende, the mineral is entirely unnoticed by the American 

 authors Shephard, Alger and Dana. 



Mr. Brooke, being desirous of stating in the forthcommg 

 edition of Phillips's Mineralogy the real composition of the 

 mineral, obtained from Mr. Nuttall some fragments, which I 

 have examined and found to be veiy pui-e blende. 



The specific gra\ity of the mineral at 60° is 4-063. Its blow- 

 pipe characters are those of common blende when pretty_ free 

 from sulphuret of iron. I could not detect cadmium in it by 

 the blowpipe, but a trace was found by employiugWollaston's test. 



Tlie mineral was decomposed by nitric acid, and the solution 

 evaporated nearly to drjmess with an excess of hydi-ochloric acid; 

 the sulphur was determined as sulphate of baryta; and the zinc, 

 after the removal of the excess of baryta by sulphuric acid, was pre- 

 cipitated from the boiling solution by carbonate of soda. The 

 analvsis afforded the following results : — 

 ^ Zinc .... 67-46 



Sulphur . . 32-23 



99-68 



The theoretical proportions of ZnS being 

 Zinc .... 67-08 

 Sulphui- . . 32-92 

 100-00 

 This slight difference is due partly to error in the analysis, and 

 partly to the fact of some of the fragments being slightly en- 

 crusted with carbonate. 



* Communicated by the Author. 



