cupelled

M. Marie afterwards took from one of the geodes a pinch of powder weighing about half a gramme, and cupelled a bright dust-shot bead weighing not less than two centigrammes.

The Land of Midian 2003

In judging these results, it must be borne in mind that it is difficult to regulate the temperature, &c., in consecutive experiments so as to get exactly similar results, so that the range in consecutive cupellations is greater than that in a batch cupelled side by side.

A Text-book of Assaying: For the Use of Those Connected with Mines. Cornelius Beringer 1886

Gold, .3 gram, was cupelled with 10 grams of lead and varying amounts of silver, and the cupels were assayed for gold with the following results:

A Text-book of Assaying: For the Use of Those Connected with Mines. Cornelius Beringer 1886

The process is as follows: -- The cupels, which should have been made some time before and stored in a dry place, are first cleaned by gentle rubbing with the finger and blowing off the loose dust; and then placed in a hot muffle and heated to redness for from 5 to 10 minutes before the alloy to be cupelled is placed on them.

A Text-book of Assaying: For the Use of Those Connected with Mines. Cornelius Beringer 1886

The following results are often quoted: -- Cupelling 1 grain of silver with 10 grains of lead, the loss was 1.22 per cent.; 10 grains of silver with 100 grains of lead, loss 1.13 per cent.; 25 grains of silver cupelled with 250 grains of lead, lost 1.07 per cent.

A Text-book of Assaying: For the Use of Those Connected with Mines. Cornelius Beringer 1886

If 10 grams of silver are cupelled with 10 grams of lead, there will be a loss of about 50 milligrams of silver, which is in round numbers 1-30th of the corresponding copper loss; with 10 grams of gold and 10 grams of lead, the loss will be 4 or 5 milligrams, which is about 1-12th of the corresponding silver loss.

A Text-book of Assaying: For the Use of Those Connected with Mines. Cornelius Beringer 1886

Three lots of 1 gram of gold cupelled each with 20 grams of lead repeatedly, so as to make 13 cupellations in all, lost in actual weight 35.72 milligrams.

A Text-book of Assaying: For the Use of Those Connected with Mines. Cornelius Beringer 1886

Copper oxidises less easily than lead does; and, consequently, the alloy which is being cupelled becomes relatively richer in copper as the operation proceeds.

A Text-book of Assaying: For the Use of Those Connected with Mines. Cornelius Beringer 1886

For example: a cupel on which an alloy consisting of 0.80 gram of silver, 0.47 gram of gold, and 25 grams of lead had been cupelled, was found to contain 7-1/2 milligrams of silver, and rather less than half a milligram of gold.

A Text-book of Assaying: For the Use of Those Connected with Mines. Cornelius Beringer 1886

It would be cupelled, parted, &c., as nearly as possible under the same conditions as the actual assays.

A Text-book of Assaying: For the Use of Those Connected with Mines. Cornelius Beringer 1886