No. VI.--TABLE of the Weights of the different Gasses, at 28 French inches, or 29.84 English inches barometrical pressure, and at 10 deg. (54.5 deg.) of temperature, expressed in English measure and English Troy weight, 490 No. VII.--TABLES of the Specific Gravities of different bodies, 491 No. VIII.--ADDITIONAL.--RULES for Calculating the Absolute Gravity in English Troy Weight of a Cubic Foot and Inch, English Measure, of any Substance whose Specific Gravity is known, 505 No. IX.--TABLES for Converting Ounces, Drams, and Grains, Troy, into Decimals of the Troy Pound of 12 Ounces, and for Converting Decimals of the Pound Troy into Ounces, &c. 508 No. X.--TABLE of the English Cubical Inches and Decimals corresponding to a determinate Troy Weight of Distilled Water at the Temperature of 55 deg., calculated from Everard's experiment, 511 ELEMENTS OF CHEMISTRY. PART I. Of the Formation and Decomposition of Aeriform Fluids--of the Combustion of Simple Bodies--and the Formation of Acids. CHAP. I. _Of the Combinations of Caloric, and the Formation of Elastic Aeriform Fluids._ That every body, whether solid or fluid, is augmented in all its dimensions by any increase of its sensible heat, was long ago fully established as a physical axiom, or universal proposition, by the celebrated Boerhaave. Such facts as have been adduced for controverting the generality of this principle offer only fallacious results, or, at least, such as are so complicated with foreign circumstances as to mislead the judgment: But, when we separately consider the effects, so as to deduce each from the cause to which they separately belong, it is easy to perceive that the separation of particles by heat is a constant and general law of nature.