HARTZ, or HAnz, a tract of mountainous country, si tuated in the kingdom of Hanover. It is about 70 miles long, and 20 broad. The forests of the Hartz have about one-third of hard wood, and two-thirds of soft wood. An Insect belonging to the order Coleoptera, nearly allied to the Dermestes typographus, has lately committed great ravages in these. forests. It infests fir trees, and in one tree 80,000 larvae have been found. The principal mine rals are lead, copper, silver, zinc, iron, green vitriol, blue vitriol, white vitriol, and sulphur. The silver mines, which are said to have been discovered in the year 968, were the first that were opened in Europe. The annual product of the lead, silver, and copper mines, is stated at 157.994 dollars.
The Editor is indebted to Professor Jameson for the fol lowing account of the mineralogy of the Hartz mountains.
This interesting tract of country is composed of primi tive transition, fIcetz, and alluvial rocks ; but hitherto no volcanic substances have been met with in it.
A. Primitive Rocks.
['hese are granite, primitive greenstone, quartz-rock, primitive flinty slate, primitive clay slate, and primitive limestone.
1. Granite. This rock is supposed to form the central part of the Hartz, and consequently to support all the other mineral strata of. this part of Germany. It is oc casionally traversed by veins of quartz, schorl, and horn stone. At its line of junction with the superincumbent strata, intermixtures of the rocks are to be observed, and even veins of the granite shoot from the massive rock into the superincumbent ones. These facts are differently explained by the Neptunian and Plutonian speculators. The Neptunists consider them as illustra tive of the cotemporaneous formation of the two rocks ; while the Plutonists view them as irrefragible proofs of the granite having been projected in a fluid form from the interior of the earth amongst previously existing strata.
2. Frimitive greenstone. This rock rests immediately on the granite, and sometimes beds of it occur in the clay slate. Like the granite, it is mag-netical, although it
contains no disseminated magnetic iron-stone or mag netical pyrites.
3. Horn-rock, (Horn-fels.) Hitherto mineralogists have not attended to this rock. It is an intimate mixture of splintery quartz and compact felspar, in which some times the one, sometimes the other, mineral predomi nates. It is occasionally coloured black with schorl. It occurs resting upon granite, and frequently intermixed with that rock at the line of junction.
4. Quartz-rock. It is either splintery, or composed of granular concretions. It rests either upon the granite, or occurs in beds alternating with greenstone or horn rock.
5. Primitive flinty slate. This rock occurs but sparingly in the Hartz, and is generally disposed in beds, alternat ing with horn-rock and clay-slate.
6. Primitive clay-slate. This rock forms beds in flinty slate, primitive limestone, and green-stone.
Metalliferous venigcnous formations in primitive clay-slate.
The following principal formations may be distinguished.
a. The veins of this formation contain principally ga lena or lead glance, native arsenic, red silver ore, with much calcareous spar, and a small portion of quartz.
b. This formation is almost entirely composed of gale na or lead glance, with a very small portion of native arsenic, red silver ore, grey copper ore, and blende.
c. In this formation, like the preceding, galena is the predominating ore, and is associated with a small quantity of grey copper ore, iron pyrites, copper py rites, red iron stone, brown iron ochre, and red silver ore.
7. Primitive limestone. It occurs but seldom, and in beds, in clay-slate.
B. Transition Rocks.
The following rocks of this class are met with in the Hartz, viz. limestone, greywacke, clay slate, whet slate, alum slate, transition flinty slate, transition trap, and transi tion porphyry.
I. Limestone. It occurs in beds, often of considerable thickness, in greywacke, and transition clay slate.