130 TRANSACTIONS OF THE [MAY 23, 
Moisture at 110°C. . : p : ae0308 
Loss on ignition . c - : er O 74: 
SiOs) Ge 5 - 2 : n - - 69.465 
FeO, . - A - : = - 3 2600 
INO e : 4 - : - : 2 Licao 
MnO . - 5 = 5 : . trace 
CaO . p 5 z 5 ‘ am e2soin 
MgO . - - - - 5 - « 102305 
tater 24. oon) eked eae en Sieh hela come 
Shs 20. eral eee eae 
97.07 
Na,O by difference . : : : 7) 2093 
Crushing-tests were made on five sample cubes with the great 
Emory testing-machine in the School of Mines, and as preparatory 
to this the specifie gravity was found on four cubes at 2.688, 2.687, 
2.684, and 2.688. After three weeks’ soaking these cubes absorbed 
water, respectively, 0.0021, 0.0021, 0.00224, and 0.0026 per cents. 
The crushing-tests gave the following results. The cubes were first 
ground and polished so that the faces next the jaws of the crusher 
were parallel within a limit of error of 0.005 inches. The cushion 
employed between the cubes and the jaws was blotting-paper. 
II. Ill. IV. a‘ 
I : 
Height in inches 2.033 1.983 2.059 2.011 2.009 
Breadth % - 2.0 2.13 2.02 IS 2.03 
Thickness ‘‘ c 2.1 ge) 2.03 2.03 2.03 
Area in sq. inches . 4.2 4.23 4.1 4.0 4.12 
Maximum compres- 
sion in pounds . 113,200 122,000 106,000 101,400 108,700 
Crushing - strength 
per sq. inch : 26,952 28,841 25,853 25,350 26,383 
The cubes exploded without previous cracking. This strength 
is exceptionally high, as the general run of granite is far less. It 
does not, however, equal the elaeolite-syenite of Little Rock, Ark., 
which was tested by the late J. Francis Williams (see Annual Re- 
port of Arkansas State Geologist, 1890, vol. ii), where results of 
over 30,000 pounds were obtained; but it is far beyond the re- 
quirements of building. 
Cubes of the rock were also boiled in acid. One which was thus 
treated for five hours in boiling dilute HCl (1 part HCl of specific 
gravity 1.20 to 20 parts H,O) lost 0.59 per cent. in weight. A 
second cube treated in the same way in boiling dilute H,SO, (1 
part H,SO, of specific gravity 1.84 to 20 parts H,O) gave a loss of 
0.48 per cent. Both these results indicate a great resistance to 
natural solvents. Two large cubes were placed in a muffle and 
maintained at a bright red for half an hour. One was allowed to 
cool just below redness and then plunged in cold water. It caused 
one crack that extended half through. The other cube was allowed 
to cool slowly in the air, and showed a thin, external, crumbling 
layer. When these results are compared with somewhat similar 
