204 FF. A. Genth’s Contributions to Mineralogy. 
I. Il. TIL. 
STE ORY 
By sulphuric acid. By carbonate of soda. 
Water, “ ‘ * not det. 20°91 not det. 
Silicic acid, - - : 51:20 51:09 51°02 
Ferrous oxyd, - - - 0-22 0-23 026 
Magnesia, - - 26°81 $6260. 
100°51 
15. Monazite. 
One crystal of this rare mineral has been found in the gold 
washings of Todd’s branch, Mecklenburgh county, N. ©., asso 
ciated with diamond, garnet and zircon, the latter similar 
form to those of McDowell Co., N. C. (Dana’s Mineralogy, 4th 
edit., page 195, fig. 886.) 
It is } of an inch long, a little over } wide and somewhat Jess 
than } thick, of a yellowish brown color and shows distinetly 
the following planes: 1, 1¢, a, Z -1 andi. The crystal being 
slightly waterworn has the edges somewhat rounded, by whi 
ap aa may have been obliterated. The sp. gr. at 12 C. 
16. Rammelsberg’s Mineralchemie. 
It is with great regret that I feel it my duty to investigators 
to call their attention to several omissions and misapprebet: 
sions in Rammelsberg’s great work, ‘‘Mineralchemie,” which I 
consider of too much importance to be allowed to pass unne 
ticed. Not intending to write a criticism of the work itself, I 
is somewhat surprising. Prof. Rammelsberg had read mt 
paper (this Journal, [2], xix, 15) he might have found that a. 
st, ; 
On page 21, he gives Shepard’s old analysis of chathamite 
(cloanthite), which was sig a any el mode of separ 
tion of cobalt and nickel was known, and in a note he adds ™Y 
recent analyses. oe 
|, O8 page 60, he states that according to Pratt the harrisite © 
the dimorphous form of the subsulphid of copper, whilst 7 
credit for this suggestion is certainly due to Prof. Shepard. ral 
‘e analyses, under No. 4, I hope will satisfy Prof. R. as ¥ 
