116 Want of Identity between Microlite and Pyrochlore. 
observations at some distance from this.line would lead us to look 
- for it about three quarters of a degree farther west than the posi- 
tion here assigned. 
P.S. Seventeen hundred Errata in Hutton’s Table of Products. 
In solving equations of condition by the method of minimum 
squares, I have been accustomed to form the products by the aid of 
Hutton’s Table. I entertained no doubt of its accuracy, until, on 
verifying oueof my operations, I discovered in. the Table an error 
which I presently perceived to run through almost an entire folio 
page. Thecase occu page 20, the product of 361 by 15 being 
given 5315 instead of 5415, and as the products appear to have 
been derived from each other by addition, this error is propagated 
to the bottom of the page, affecting thus 1700 products. 
Art. X.—On the Want of Identity between Microlite and Pyro- 
chlore ; by Cuarres UpHam SHEPARD, M. D., Prof. Chem. in 
the Medical College of the State of South Carolina, 
** Pror. Smuiman having apprised me on my recent arrival in 
town, that a paper was about to appear in this Journal by I : 
Tescnemacuer and Hayes of Boston, the object of which would 
be to establish the identity of Microlite with Pyrochlore, and being 
permitted by the editors, I hasten to reply in the same number... 
The opinion of the identity originated with Mr, Tescuema- 
cHer; and is expressed without the slightest reserve, resulting 
as he remarks, “from a close examination of several erystals of 
the mineral named Microlite;” but Mr. T. singularly enough 
omits altogether, the results of any researches bearing on the 
point to be established, if we except-the mention of a minera- 
logical property which is simply descriptive, never character- 
istic, viz. the circumstance that in Microlite, the color is “ trans- 
parent (!) straw-yellow to brick-red and dark brown!"* For the 
fall confirmation of his opinion, he then refers to the analysis of 
Mr. Haves, which was undertaken at the request of the Chem- 
les Society WE Baqinn. oe SP aD ss 
* In this account of color however, my speciiuens do not agree. 
owe 
£ 
