Cronstedt Min. § 173. 6. Minera argenti griſea. In the province of Dal[[63]].
It contains ²⁴⁄₁₀₀ of copper, ſeldom ⁵⁄₁₀₀ ſilver.
ARGENTUM (ſilver), mineralized by ſulphur, arſenic, antimony and iron. Plumoſe.
Cronstedt Min. §173. 5. Federertz of the Germans[[64]].
It ſeldom contains more than a few half ounces of ſilver in the hundred weight.
It is abſurd to found ſpecies upon the differences of the matrix: theſe ought to be conſidered elſewhere.
HYDRARGYRUM,
OR
QUICKSILVER.
Its ſpecific gravity is 14,110. It has been erroneouſly ranked among the brittle metals, for at 654 degrees below 0 it freezes[[65]], and then ſpreads under the hammer like lead. But as ſuch an extreme degree of cold rarely happens unleſs artificially produced, we ceaſe to wonder why it is always liquid or rather melted.