Mineralogy and Geology. oe 397 
talic acid. Its vapor density at 360° was found to be 12°8 and at 
440° 13-0; for a condensation to 4 vols. the eee E: TaCl, (Ta=182) 
facia give 12°5. The density of tantalic acid eig wee a 
the chlorid by ammonia ond ignited to low rettnacs was 
omptes Rendus, |xiv, 29 - = 
II. MINERALOGY AND GEOLOGY, 
1, On the Ade tf the ag ai gi ing Rocks, of California; b 
W_. Eee ~Jn the last number of this Jour urnal (this gees 
ume, p. 2 66), i in a note on the Carboniferous ges of the gold- 
bearing rocks of California, by Prof. W. P. Blake, he complains 
of a single sentence in a previous article of mine (this Jour., July, 
1866, p. 116), beginning with “and in the ied pages of the same 
work he paves the w. way for priority of disco 
I beg here to say that I regret using the pixeoind imputation in 
that sentence, and willingly retract it. It should not e bee 
written, however great the rovocation, and I sateaially | regret 
that article, and is now used to call attention bisa from the ques- 
tion there discussed to the alleged personal griev 
That article by me was written in defense of the Geological 
the paragraph already 1 referred to, says, “ he controverts the wri 
Sa stateme ae be * by partially citing vatanaee pam my 
rt, ” 
ge have no desire to misrepresent him nor his rae 
Thasmuch as he commits the same yas he accuses = of, by but 
artially citing paragra hs” from the same report, 0: 
Pavers su Fa 52 ae paca, I would sheveloes respec ully 
suggest that any parse curious in this matter should : 
whole of those portions of his report which bear upon this 
tion, and then form his own opinion as to what they really m mean 
and what Shey are worth. (Geological Reconnoissance in Califor- 
nia, p Vv, p. 276, 278 ae 279.) It will be more suggestive 
if these end entire parses santa with his later pamphlet 
oe are cited, other — 
reserved for the Emad Survey to show that the gold- beat 
ere not of these older periods. is an error, inas- 
show” this very thing, and I brought forward 
gee of the statement. I do not see the error — 
of, inasmuch as he does no t moot a single item of 
these se proofs, t bat instead offers some of his old surmises. 
