42 The American Geologist. January, i899 
Potash 0.80 
Manganese trace 
New earth, not taken up by sal ammoniac. ... 10 to 12 p. c. 
Water 18.00 
He remarked that: "Leaving out of account the supposed 
new earth the chemical composition comes nearest to saponite 
and soapstone." He reports it from the vicinity of Baptism 
river. 
This mineral is considered saponite by Dana.* 
At the mouth of Knife river (91 B) and continuing to 
Gooseberry, and at numerous other places, this substance has 
been met with. It has marked phN^sical characters, being 
tjuite soft, soapy to the touch, dirty white or gray, filling cavi- 
ties in porous trap rock, and is sometimes very abundant, ap- 
pearing where the rock is permeated by decay. 
The masses containing this substance dififer in structure 
and composition. The larger masses at Knife river are a gran- 
ular aggregate, slightly pinkish white, whose hardness is be- 
tween that of talc and gypsum (1.-2.). I^uit they are often 
non-homogeneous, embracing, along with thalite, which gives 
them a general soapy feel and an apparent softness, many 
grains of calcite, quartz, and apparently of laumontite. 
The mineral which (it is to be assumed) was examined by 
Owen and named thalite is found in its greatest purity in the 
smaller cavities, and as secondary fillings in the larger masses 
It has a general amorphous appearance but in reality it is finely 
fibrous. It forms a jelly with HCl, and its specific gravity is 
2.20. 
The examination of a thin section shows vermicular crys- 
talline aggregates which recall the ripidolites (helminth) and 
kaolinite. The vermicular bodies, as crossed by the random 
sections, present a confused and varied aspect — sometimes 
imperfectly spherulitic, sometimes bands formed by minute 
transverse fibres, sometimes bundles of fibres presenting their 
transverse sections, and frequently so mingled that no orderly 
arrangement is observable. The minute fibres, which are 
transverse to the vermicular bodies have positive elongation 
and parallel extinction. The bisectrix is //g, parallel with the 
fibres and the optic angle (2V) appears small. It is to be found 
*System of Mineralogy, 1892, p. 682. 
