20 A TREATISE ON THE CONNECTION OF

heat. This is capable, by certain processes, 6f being disengaged from those bodies, and of becoming manifest to the senses, or of passing and entering into a state of

combination with other bodies.

The frequent changes in the degree of heat and cold in the atmosphere, are to be ascribed more to the’ alter- nate disengagement and fixation of heat, by chemical

combination, than to the effects of the solar rays.

SALINE SUBSTANCES

ARE compounds, consisting of different combinations

and proportions of earth, gasses, water, and the prin-

ciple of heat; to which must be added(although not yet

treated of) the results of more compounded substances,

such as animal and vegetable matter.

Saline substances consist of acids, alkalis, and neutral salts, resulting from the combination of acids with earths and alkalis. These are stated hereafter in separate tables, wherein their uses and properties, as applicable to agri-

culture, are more fully explained. VEGETA-

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