443 
[Wright. 
ened, the particles adhered together with much less tenacity than 
is seen in the common, sticky drift clays, yet there was enough ad- 
hesion to form a plastic mass. 
The second element in the material consisted of grains of quartz 
and possibly of other minerals, scattered at random through the 
finer substance. In size, these will measure from one-sixteenth to 
one thirty-second of an inch and smaller. They are sufficiently 
numerous to make the whole material gritty and to account for the 
roughness of some of the tool- work. Many of these come just to 
the surface of the body, as, for example, three on the back between 
the shoulders, three or four on the inner side of the left leg, and 
one on the front of the arm at the right shoulder. Upon the right 
hip is one that projects a little, not having been sufficiently pressed 
down by the moulding tool. One was taken from the interior of 
the leg, at a point of fracture, and the rough summit of the head is 
liberally supplied with them. The loose grains which are lodged 
in the crevice between the right arm and the body, and which are 
shown in the photographs and engravings of the image, are of the 
same sort. These grains were, in my opinion, not accretions from 
without, cemented there by the slow deposit of ferric oxide, but 
were constituents of the original material, thrown out by the point 
of the graving tool and left where they are, either by accident or 
design. 
The material of the image was so friable that it would have been 
well nigh impossible to make a thin section for microscopic exam- 
ination. It was not attempted, and it would have been of no value 
unless the image were carved from a piece of rock. Samples of 
the finer material of the image, however, in the form of powder, 
were mounted in balsam and submitted to optical examination. 
The object in view was to obtain a clew as to the source whence 
the material of the image was derived. The microscopical exami- 
nation was not made thoroughly exhaustive because, before it was 
finished, other satisfactory evidence on this point came in. Still, 
the principal elements of the powder were determined, as follows : 
First, and most prominent, constituting more than half of the 
material, quartz , in brilliant, sharp-angled fragments. The colors 
upon revolution between crossed nicols were frequently from bril- 
liant blue to yellow, but for the most part they brightened only in- 
to a cold gray. Quite a number of the larger grains were sketched 
in outline with a camera and measured, the average mean diame- 
