112 I. C. Russell—A Solid Hydrocarbon in the 
will say nothing: partly because to do so would transgress the 
limits which I proposed to myself at the outset, and partly 
because after reading and re-reading severa times I find it 
impossible to hold any clear image of the new theor ry in my 
mind, and I fear gras ge a I might do the author injustice, 
Berkeley, California, April 1, 
Art. XI.—On the oceurrence of a Solid not heart in the 
Eruptive Rocks of New Jersey; by I. C. Rus 
(Read before the New York Academy of Sciences, April 29, 1878.) 
IN an article by T. Sterry Hunt, published in this Journal in 
1863,* mention is made of an interesting locality at yn 
Gaspé where a trap dike intersects the sedimentary rocks. 
cavities in the trap are frequently lined with chalcedony, or 
with crystals of calcite or quartz, and filled with petroleum 
which in some cases has assumed the hardness of pitch. 
Recently our attantioti was called to a newspaper spice” of 
— occurrence of mineral oil in the lava of Mt. Etna. The 
umerous round or irregular cavities contained in the inte are 
deacrtbed as being coated with aragonite and filled with min- 
eral oil. An analogous instance in our own country has been 
familiar to me for some time, which, taken in connection with 
the occurrences mentioned oct seems to be of sufficient 
interest to be worth rec 
Associated with the xhuer” of trap rock known as the First 
trap passing into a metamorphosed shale. In this region it is 
frequently impossible to distinguish in small exposures, the 
genuine trap from the metamorphosed shales that rest in con- 
tact with it.+ Many of the cavities in the amygdaloidal rock 
are filled with a brilliant jet black carbonaceous mineral 
resembling very closely the albertite of New Beanewerd 
These cavities are frequently tubular in shape, having a length 
out se = ae a coating of quartz or calcite a line or 
1. XxXxv, p | 
+ So0 article by ie erti “On the Sakvasive Nature of the Triassic Trap 
Sheets of New Jersey,” in this Journal, xv, 277, 1878. 
¢ The occurrence of “bitumen” in am: amygdalo id trap is briefly mentioned by 
8. Dana in an article on the Trap Rocks of the Connecticut Valley. Am. gt OC. 
Sci., 1874, B 47 [also, with an explanation of its origin, by G. W. Hawes, 
Journal, i ix, 456, 1875.] 
