-------------------------------------------+----+-------+---------------+---- DESCRIPTION OF SAMPLE. | | Water | Assay on | ------+--------------------+---------------| |Lost at| the Dry | Date. | Material. | Weight. |No. |100° C.|Material. | DR ------+--------------------+---+---+---+---+----+-------+---------------+---- 1889 | |ton|cwt|qrs|lbs| | | | Feb. 1|Tough cake copper | | | | | 482| |Arsenic, 0.52% | 7 " |Tough cake copper | | | | |2082| |Arsenic, 0.63% | 7 " |Tough cake copper | | | | | 491| |Arsenic, 0.68% | 7 | | | | | | | | | Feb. 2|Nickel disc for C.R.| | | | | X | |Copper, 73.75 | 7 | | | | | | | |Nickel, 24.34 | | | | | | | | |Iron, 2.18 | | | | | | | | | ----- | | | | | | | | | 100.27 | | | | | | | | | ------ | " |Silver precipitate, | | 24| 1| 0| 73| Not | | | 4 casks | | | | | | det. |Silver, 4.851 | 10 | | | | | | | |Gold, 0.0215| | | | | | | | |Lead, 19.37 | | | | | | | | |Zinc, 2.00 | | | | | | | | |Silver, 1584.7 | | | | | | | | | ozs. per ton | | | | | | | | |Gold, 7.0 | | | | | | | | | ozs. per ton | " |Purple ore |200| | | | 494| Not |Copper, 0.13% | 11 | | | | | | | det. |Sulphur 0.15% | ------+--------------------+---+---+---+---+----+-------+---------------+---- When the number of samples is small, the Sample Book may be omitted, and the entries made in the Assay Book as the samples arrive. _Report-forms._ These should entail as little writing as possible in making out the report. For general purposes the form given on p. 12 is useful. ~The quantity of substance~ to be taken for any particular assay depends largely upon the method of assay adopted. There are, however, some general considerations which should be remembered, and some devices for simplifying the calculations which should be discussed. The smaller the percentage of the substance to be determined, the larger should be the amount of the ore taken. The following table will give a general idea as to this:--