The new chemistry / by Josiah P. Cooke, Jr.

  • Josiah P. Cooke
Date:
1876
Catalogue details

Licence: Public Domain Mark

Credit: The new chemistry / by Josiah P. Cooke, Jr. Source: Wellcome Collection.

    121/376 page 115
    LAW OF MULTIPLE PROPORTIONS. bine, tlie union takes place in definite proportions by weight or volume. But tliis is not all the truth. There is a law governing the definite proportions, and the proportions of the difierent elementary substances which unite to form the various known compounds are so related that it is possible to find for each ele- ment a number, such, that, in regard to the several numbers, it may be said that the elements always com- bine in the proportion by weight of these numbers or of some simple multiples of these numbers. This supplement to the law of definite proportions is known as the law of multijjle proportions; but, if we accept the atomic theory, both laws are merely necessary con- sequences of the constitution of matter which this the- ory assumes to exist. Let us, in the first place, under- stand fully the facts, and we shall then be prepared to consider their bearing on our theory. In the list of chemical elements above there has been placed against the name of each substance a num- ber which, for the present, using a term suggested by Davy, we will call its proportional number. JSTow, the same elementary substances frequently combine with each other in several definite proportions, but these proportions, estimated by weight, are invariably those of these numbers or of their simple multiples. For example, there are two compounds of carbon and oxy- gen, which contain the relative number of parts, by weight, of each element indicated below: Carbonic oxide, Carbonic dioxide, Carbon. Parts by woiglit. 12 12 Oxygen. Parts by weight. 16 32 There are five compounds of nitrogen and oxygen whose composition in parts, by weight, is as follows:
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