392 The America?i Geologist. December, lao 
and the cla)'-slate; of euryte between the clay-slate and 
limestone; and a narrow belt of transition in the extreme 
northeast portion. "The gneiss," he says "which contains 
here and there some subordinate formations, runs in a direc- 
tion generally from northeast to southwest. The subordin- 
ate formations of this gneiss are the diabase (i) and the 
pegmatite (2), in which sometimes the feldspar occurs of 
an earthy appearance or kaolin (3), being abundantly in- 
tersected by veins or, properly speaking, strata or eurite 
(4)." The "Talcose or serpentine formation" occurring 
near Chestnut hill is described as of a dark green approach- 
ing to black color, and in it he finds the "steatitose stea- 
schiste" which is used in Philadelphia under the name of 
soapstone. 
The rock which is colored on the map as eur)te he de- 
scribes as being equivalent to the weistein of Werner, and 
he naively remarks: 'T am much delighted at meeting this 
rock for the first time this side of the Atlantic. I imagined 
myself transported to the Erzgebirge in Saxony, and re- 
membered with renewed pleasure the father of geology who 
made us acquainted with it." 
The mineralogical character of the rocks is described in 
considerable detail in the first fourteen pages of the pam- 
phlet, the remainder being given up to a description of the 
soils and their physical and chemical composition. The 
work is naturallv of purely historical interest, but in \iewof 
the statment of Marcou as quoted above, seems worthy of 
note here. g. v. m. 
