Part 20

Its ſpecific gravity is 14,110. It has been erroneouſly ranked among the brittle metals, for at 654 degrees below 0 it freezes, 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.

Nitrous acid diſſolves it readily, vitriolic acid requires to be aſſiſted by a boiling heat; muriatic acid does not act upon it all, unleſs previouſly deprived of as much phlogiſton as in 100 parts may be called 74. The attractive power wherewith it retains this portion of phlogiſton occupies the fourth place in the ſeries; that is, it holds it leſs ſtrongly than the noble but more ſtrongly than the baſe metals.

§ 173.

HYDRARGYRUM nativum (quickſilver native). Native.

CRONSTEDT Min. § 217.

Whether it be entirely free from every metallic contamination I have not yet tried.

§ 174.

HYDRARGYRUM (quickſilver), united to ſilver. Amalgamated.

CRONSTEDT Min. § 217.

§ 175.

HYDRARGYRUM (quickſilver), mineralized by muriatic and vitriolic acids. Hornlike.

Mineralogy owes the diſcovery of this to Mr. WOULFE. Phil. Tranſ.

§ 176.

HYDRARGYRUM (quickſilver), mineralized by ſulphur. Cinnabarine.

CRONSTEDT Min. § 218. Cinnabaris.

§ 177.

HYDRARGYRUM (quickſilver), mineralized by ſulphur and iron. Martial.

I am doubtful whether this be a diſtinct ſpecies. The iron perhaps is only mechanically diffuſed.

§ 178.

HYDRARGYRUM (quickſilver), mineralized by ſulphur and copper. Cuprous.

CRONSTEDT Min. § 219.

PLUMBUM, OR LEAD.

§ 179.

Its ſpecific gravity is 11,352, greater than that of any other of the baſe metals. The nitrous acid perfectly diſſolves it; the muriatic more difficultly; the vitriolic hardly at all, for the vitriol of lead being inſoluble in water incruſts the metal, and prevents its ſolution. After calcination the weakeſt vegetable acids diſſolves it, and acquire a ſweet taſte. The phlogiſton neceſſary to be taken away in order that it may diſſolve may be called 43, which is leſs than that of any other metal. Hence we underſtand why the calx of lead may be reduced with a very minute quantity of inflammable matter. With reſpect to the force wherewith it retains this phlogiſton it occupies the tenth place. It melts at 595 degrees of heat.

§ 180.

PLUMBUM nativum (lead), though many mineralogiſts doubt whether it has ever yet been found. Native.

§ 181.

PLUMBUM (lead), mineralized by vitriolic acid. Vitriol of.