TJioinnx Sfi-rr;/ limit. — Frdr^tf. 3 
which four voars afterwards heeauu' tlu' .Vuiericau .Vssoeialioii for 
the Advaiicciuent of Science, l)r. V. T. Jackson made a coinimi- 
nication •■On the copper and silver of Kewenaw Point." an<l 
Prof. II. I). Rogers ••suhniitted some remarks on the ([Uestion of 
the Tacoiiic rocks," Arc, wliicli the spcakt-r Itelieveil to Ije •■only 
the well known lower Appalachian strata disiiuised by some altera- 
tion of mineral tvpe induced hy ii;neous metamori)hosis. '" These 
two sulijects were destined to receive lireat attention at the new 
member's hands down to tlie last days of his life. 
At the lirst nieetinir of the A. A. \. S.. held in IMiiludeliihia. 
September. 1 S4S. I'rof. Hunt read a |)a|)er --On .Vcid Sprinus and 
(ivpsum Deposits of the ()nonda<>a Salt (rroui)."' and at this meet- 
ing Piofs. AV. li. it W. H. Piogers read a })aper ou -'The Ccjmpar- 
jitive Soluliility of the ('arl)onate of I.inie and Magnesia." estab- 
lishinu' till' fact that in water ini[)regnate(l with CO.,. carbonate 
of magnesia is UKjre sohible than carl)oiiale of lime." The study 
related to tlie foru)ation of dolomites, and c<)ntained the germ of 
an idea splendidly di'veloped Ity Dr. Hunt in after years in con- 
nection with the cause of the difference in per cent, of magnesia 
of the limestones deposited in the ohlest and tiiose in the newer 
geological seas. One might easily and perha[)s pi-olilabjy trace the 
origin of many investigations whicii Dr. Hunt has [)ursued to 
brilliant (.liscoveries in the sometimes vague, tint to liim. suggestive 
(piestions and observations at these scientific meetings. He re- 
mained in Vale for about a year and a half, until some time in 
1S4(). as the assistant of I'rof. 1>. S. Silliman. Jr.. ihrougli whose 
aid and that of Prof. Penj. Silliman. Sr. . he ol)tained the appoint- 
ment of chemist to the geological survey of A'ermont, under tiie 
charge of Prof. ('. !>. Adams. 
The year following, on the death of .Mr. Deiinison Olmstead. Jr., 
whose place on the A'ermont survey he iia<l taken when AFr. Olm- 
stead assume(| similar duties for tlu- geological survey of Canada, 
Mr. Hunt again stei)petl into the vacated position and moved to ^lon- 
treal. where began that intimate ;tssocialion with the chief geolo- 
gist, Sir William Logan, which was to last for twenty-five years, 
or from 1S47 until IS72. During a part of this time he lectured 
on chemistry (in French) at the University of Tiaval (1 sr)(i-"(»l!), 
and for four years on chemistry and mineralogy at .AIc(rill I'ni- 
versity. liesides these duties and the ai)soil)ing work of the 
geological survey which recpiired not only his research in the labo- 
