Page:Report of the seventh meeting Australasian Association Advancement of Science.djvu/105

Rh soils. Lately a great deal of attention has been given to this subject; but it is by no means a new one, for Professor Delesse published in the Ann. des Mines in 18G0 a long- investigation upon the occurrence of nitrogen and organic matters in rocks^ entitled "De l'azóte et des matières organiques dans l'écorce terrestre."

In this he gives the amount of nitrogen obtained from 104 varieties of crystalline and sedimentary rocks from different parts of Europe, including various calcareous rocks, grits, sandstones, marl, and alluvial soils.

They all yielded nitrogen ; most of them gave ammoniacal, but others acid, products on distillation. Some gave acid products at first, followed by alkaline ones, and a tarry odour. The nitrogen was, doubtless in many cases, present as organic compounds.

Some years ago, 1873-4, I examined a large number of minerals and rocks for "organic matter," and found that rock-crystal, amethyst, topaz, and many other minerals, gave off gases and ammoniacal empyreumatic distillates, but the investigation had to be laid aside, and the results have not yet been published.

Hugo Erdmann (Ber., 1896, 29) has also found that a number of minerals which occur in ancient igneous rocks evolve ammonia when warmed with pure soda solution, and he has estimated the amounts; thus a mineral resembling polycrase gave •028 per cent. of nitrogen evolved as ammonia. Another mineral resembling euxenite contains •005 per cent. of nitrogen. He states that many other minerals from the north of Europe also contain nitrogen^ such as ytterspar, euxenite, fergusonite, gadolinite, and æschynite. Professors Ramsay and Tilden, working independently, however, did not find nitrogen in most of the minerals examined by them.

It was known that hydrocarbons, carbon monoxide, carbon dioxide (in both the liquid and gaseous states), nitrogen, and other gases occurred in rocks, but they found D