172 Canadian Record of Science. 
black shale filled with fragments of trilobites and crinoids. 
In these analyses the carbonates of lime and magnesia, with 
the alumina and oxide of iron, were removed by solution in 
acids, and the elements of the organic matter determined 
in the insoluble portion. 
Me II. Ill. IV. V. 
@lay and’ sand:..°.>..... 38°45 34:60 37:26 48:27 | 73nbm 
Car Wonlererereeheieirlensoietelcls 6°83 6°63 61 6:99 15°08 
Ja hyGlivoyeilis dosaodooon Gone 74 SU 83 H-13 1°65 
Oranges sono beouseooadde 3°20 2°96 boy Al 3°39 5°39 
Carbonate of lime........ 45°02 49°31 5260 20°30 1-29 
Carbonate of magnesia... 2°09 2°53 3°42 11:48 °76 
Alumina and oxide ofiron. 2°16 2°09 3°29 7°99 2-79 
98°49 98°89 99°72 99°55 100°48 
‘“‘The analysis V in the above table is that of a pyro- 
schist from this formation, in the lead region of Wisconsin.” 
The first four analyses are made from Canadian speci- 
mens, and give us a sufficiently typical series from remote 
outcrops of the Utica terrane, from which the lithological 
and chemical characters of the rock may be ascertained. 
Mineralogical characters.—The minerals which charac- 
terize the Utica are not numerous, but it may be stated 
here that iron pyrites is tolerably abundant in the middle 
beds of the Utica, about Ottawa where :t occurs in masses 
from the size of a man’s fist to smaller dimensions, and 
often replacing entirely or simply coating organic remains, 
such as orthoceratites, trilobites, graptolites and sponges. 
Strontianite has also been observed, determined and 
recorded by Dr. B. J. Harrington from the Utica shales 
of St. Helen’s Island, opposite Montreal, Que. 
Selenite.—A variety of gypsum occurs in fine seales or 
flakes either coating organic remains or between divisional 
planes of stratification as a secondary product of the 
decomposition of iron pyrites. 
The Utica, except in its lowest measures, does not afford 
any building stone of any consequence. 
A few of its calcareous strata, close to the base of the 
formation, might be utilized for building purposes, but they 
