SCIENTIFIC AND LITERARY NOTES. 267 
relative to the scholastic controversies of the middle ages, viz., that to 
argue a subject well, the two parties must know nothing of it, seeing 
that if one understands something of it, the discussion is soon ended, 
and that when both see it clearly they cannot even commence. 
Lastly, if the astronomer has succeeded in foretelling the movements 
of the celestial bodies because he has found out the laws of them, may 
we not hope with Condorcet that, if once the present condition of 
humanity be well understood as a necessary result of its past, we may 
succeed in sounding a little the mystery of its future! We are 
studying the past in order to goraprehend the present, and possibly to 
obtain a glimpse of the future. M. M. K. 
SCIENTIFIC AND LITERARY NOTES. 
SALT WELLS OF MICHIGAN. 
Professor Winchell has sent us a copy of his paper on the Saliferous Rocks 
and Salt Springs of Michigan, published in a recent number of the American 
Journal of S-ience (November, 1862). According to the author, the brine- 
holding strata of Michigan occupy three distinct geological positions. The 
lowest saliferous beds form part of the Onondaga Salt Group of the Upper 
Silurian Series, but these have not as yet been thoroughly explored. Seven 
hundred and fifty feet above the Onondaga deposits, lie the strata known as the 
Michigan Salt Group, the source of supply being probably the “‘ Napoleon Sand- 
stone” at their base. These strata have been fully discussed by Prof. Winchell 
in his “ lirst Biennial Report.” They belong to the horizon of the upper part of 
the Carboniferous linestone formation. Still higher in the series, the so-called 
“Parma Sandstone,” immediately beneath the coal-measures proper, has been 
found to furnish a third supply of brine. The wells first sunk at Bay City, 
derived their supply from this source, but the borings are now carried down to 
the lower-lying Napoleon sandstone. The daily supply from these wells, along 
the Saginaw Valley, is stated to be “‘at least 25000 gallons each ”—their united 
daily produce, with 22 blocks of kettles in operation, being about 1210 barrels. 
The cost of manufacture, per barrel, does not exceed sixty-four cents. 
FOSSIL REPTILES FROM THE COAL-MEASURES OF NOVA SCOTIA. 
The bones and other portions of Carboniferous reptiles, discovered some time 
ago by Dr. Dawson in Nova Scotia, have been examined by Professor Owen 
(Journal of Geological Society, August, 1862). The materials collected are 
referred to several distinct species of Hylonomus and to one species of Dendrer- 
peton: genera belonging to the Ganocephalous Order of Professor Owen's last 
classification. The author observes :—‘' Dendrerpeton, like Hylonomus and Ar- 
chegosaurus, shows the affinity (if it may be so called) or analogy to the ganoid 
