The student will require the following apparatus, which he may either purchase or obtain on deposit, making good any breakages according to the practice of the laboratory. Gallenkamp's numbers are again given as a guide, though several other English firms supply goods of equal quality This apparatus is additional to what he already has.

...

2 cylinders, 100 c.c. and 1000 c.c.

Pipettes, one 10 c.c., one 25 c.c., one 50 c.c., and one graduated.

1 thermometer, 0°-300° C.

6 litre bottles for storing standard solutions.
2 test tiles (eight holes each), porcelain.
1 bead hammer.

1 Cupel tray (sixteen divisions).

1 steel spatula (20 cm.).

12 sheets of glazed paper (stout for assaying).
2 annealing cups.

2 parting bulbs.

Generally the following Apparatus is supplied by the Laboratory :

Balance.

Water oven, air oven.

Hydrometers.

Diamond mortar, sieves, agate and steel mortars.

Hot plates, combustion furnace and fittings.

All the more complicated glassware and other apparatus.

Furnaces, grinding appliances, furnace tools, gold rolls, etc., required in assaying. Any special apparatus required in technical analysis.

The student may procure or obtain on deposit

1 box gram weights.

1 box assay weights.

Platinum crucible (30 c.c.).

Also it will be more convenient if arrangements be made to obtain all crucibles, scorifiers, and other assaying stores from the laboratory stores as required, as such materials take up too much of his locker space. Such stores to be given out once a week.

The above lists include most of the ordinary requirements. Any additional apparatus may be procured during the course.

QUANTITATIVE

ANALYSIS.

CHAPTER II.

INTRODUCTORY.

In the course of work completed, the problem so far met with has been the determination of the various elements (or compounds) present in a substance. In an ore, for instance, there may be present silica, iron, copper, arsenic, and sulphur, and it is the province of qualitative analysis to determine the presence or absence of these and other elements. It is obvious, however, that there still remains an unknown factor, namely, the quantity of each element present in any given substance. Having found that the ore contains the substances mentioned, the student is now asked how much silica, iron, copper, arsenic, and sulphur by weight are present in one gram or other convenient weight of the ore.

It may be said, then, that the province of quantitative analysis lies in the determination of the quantities-either by weight or by volume-of the various elements present in a substance. This substance may be a solid, liquid, or a gas.

Such an analysis may be either proximate or ultimate. For example, if one gram of salt be mixed with one gram of iron pyrites and the mixture be analysed, we may

(1) Extract the salt with water and leave the iron pyrites as a residue. By filtering and evaporating the solution to dryness, the salt may be estimated; and by drying and weighing, the iron pyrites may be estimated.

(2) The formula of salt is NaCl, and of iron pyrites FeS. By methods given further on, we may estimate the Na, Cl, Fe and S present by four separate determinations.

In the first case, where compounds are determined, the analysis is termed proximate.

In the second case, where elements are determined, the analysis is termed ultimate.

For convenience, quantitative methods may be classified thus: