100 J. D. Dana—Address of T. Sterry Hunt. 
1859. Again, in the Review published in 1872, after stating 
the fact of the occurrence of m magnetite in mica, ascertaine y 
Prof. Brush, as an example of envelopment, he next mentions a 
pseudomorph of tale after enstatite. Thus he declares his 
belief in the old views to the present year, excepting, as I have 
said, only a few species not bearing on the question here under 
consideration. Delesse, in adopting in 1861 the by pote 
with regard to beds of serpentine just stated, did not assume 
or imply that serpentine pseudomorphs or poser were so 
was aware that the method was wholly in- 
pseudomorph of chrysolite had been made by the 
alteration, not of a hydrous magnesian silicate, but of a crystal 
opinions by “‘ hazarding the amd “4 “nd Delesse wrote his 
views on envelopment and petaeOrphie “while he still 
inclined to the views of the opposite school.” Thus, Delesse’s 
direct and consistent account of his views is set aside on the 
ground of stupidity, or his not knowing clearly what he 
believed—a damning apology for Delesse, Engineer-in-Chief of 
the Mines of France, if it were needed: but, not needed, most 
damaging to the argument of his apologist.* 
OssEcTION 3. That Prof: Hunt makes Naumann sustain the 
theory of envelopment, when, in fact, this veteran teach 
and mineralogist presents the ordinary views on pseudomorphism 
tn the successive editions of his Mineralogy down. to ais last of of 1871. 
In reply to this Mr. Hunt adds one more sentence to the citation 
in his Address from Naumann’s published letter to Delesse. 
But Naumann’s letter related only to Delesse’s ideas on envelop- 
ment, and is utterly misused by Prof. Hunt. I repeat from my 
former article that Naumann’s chapter on Pseudomorphism 
contains not a word on envelo — i val it does eg the 
old views; and his work is full o: rye according there- 
with. Even fahlunite and some how es are admitted to 
be (p. 455, note) products of the alteration of iolite,t contrary 
to Sikacer and Hun 
* In my review, I did not say, as as Mr. Hunt implies, that Delesse does not in any 
way countenance the views of Mr. Hunt, for I remarked that he did agree with him 
with regard to the ese hae of serpentine, and with respect to the envelop- 
ment nature of a few of the kinds of pseudomorphs; but I did say that with 
to pseudomorphs of serpentine and all the species under dispute, as well as most 
other kinds, mie ake regard to the use to be made of the facts under envelopment, 
Delesse h i opposite views to those of Mr. 
¢ Nauman, ts icon aeice omen to th his Mineralogy of 1871, alludes to 
Haidinger’s “ excellent article” on the relations of fahlunite, chlorophyllite, pinite, 
