_Laboratory Book._ This is the Assayer's note-book, in which he enters clearly the particulars of his work--the results obtained, as well as how these results were arrived at. The calculations should be done on scrap-paper, and should not be entered, although, of course, detail enough must be shown to enable the results to be recalculated. EXAMPLE OF PAGE OF LABORATORY BOOK. ______________________________________________________________ Purple Ore 5 grams 19/10/89 0.0042 grm. 0.0021 " ------ Colorimetric 0.0063 × 20 = 0.13% Copper ______________________________________________________________ 482 Tough Copper 10 grams Feb. 1/89 10.5 c.c. Uranium. = 0.52% Arsenic ______________________________________________________________ 2082 Tough Copper 10 grams 12.7 c.c. Uranium. = 0.63% Arsenic ______________________________________________________________ 491 10 grams Tough Copper 13.7 c.c. Uranium Feb. 1/89 = 0.68% Arsenic ______________________________________________________________ Standard of Uranium acetate. 0.150 gram As_{2}O_{3} = 23.3 c.c. Uranium. .'. 100 cc. Uranium = 0.5 gram As. ______________________________________________________________ 10071 5 grams Tin Ore Cruc. and SnO_{2} 9.6065 grms. Feb. 3/89 Cruc. and Ash 9.4235 " ------ SnO_{2} = 0.1830 = 2.88% Tin ______________________________________________________________ _The Assay Book._--This is the Official book, and is a combination of the Sample and Laboratory books. It corresponds with the report-forms. Without being loaded with detail, it should contain sufficient to characterise each sample. Key to following example page of Assay book: DR = DATE REPORTED. Not Det. = Not detected EXAMPLE OF PAGE OF ASSAY BOOK.