[24] It is mentioned by the author, as a chemical test or reagent: it may, by decomposing it by ignition with charcoal, or with an alkaline carbonate, be made to afford its earth for the preparation of barytic tests, but we are not aware that it is itself ever used as a test.

[25] They are attributed by the author to phosphorus. Is it supposed to be in the form of phosphuretted hydrogen? May not these be electrical phenomena?

[26] According to Dr. Meade, the Missouri ore affords only a trace of silver. (See Bruce's Minl. Journal, vol. 1, p. 10.)

[27] Mr. Schoolcraft thinks it may yield seventy per cent.—it gave him by analysis eighty-two per cent.