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APPENDIX.

Very extensive tables of this sort are given in chemical books ;they are exceedingly useful for many purposes, and greatly assistthe memory in learning the composition of compound substances.Ammonia for instance consists of one equivalent of Nitrogenand three of Hydrogen; hence we know that every 17 parts byweight of that substance contain 14 parts of Nitrogen and 3 partsof Hydrogen, and from this it is easy to reckon the exact quantityof Nitrogen in 100 parts, or in any given weight of Ammonia.

B.—COMPOSITION OF VARIOUS ORGANIC SUBSTANCES.LIGNIN .

Carbon .

. 4980

Oxygen .

.

. 4462

Hydrogen

GUM.

. 558

10000—Prout.

Carbon.

...

. 4268

Oxygen .

.

. 5095

Hydrogen

CANE SUGAR.

. 637

10000— Berzelius.

Carbon.

. 4499

Oxygen .

.

. 4860

Hydrogen

GRAPE SUGAR.

. 641

10000— Berzelius.

Carbon.

.

. 3671

Oxygen .

* * . •

. 5651

Hydrogen

STARCH.

. 678

10000— Saussure.

Carbon.

...

. 4425

Oxygen .

. 4908

Hydrogen

.

. 667

10000—Berzelius.