That any of your tutors, or any of the friends of this institution, wish to promote reformation, in church or state, by any other means than those of reason, and argument, is a _calumny_, utterly void of foundation, or probability. But your conduct, dispersed as you will soon be in different parts of the country, will be the best means of refuting it. Let us leave the method of proceeding by _riot_ and _tumult_ to those persons to whose schemes such proceedings are congenial. Truth stands in no need of such support, and will always triumph when assailed by such weapons. In return, then, for the advantages which you have enjoyed in this institution, do it this service; and in recommending it, I trust you are doing substantial service to the cause of liberty and truth; and conferring a most important benefit on your country, and on mankind. CONTENTS. LECTURE I. _The Introduction_ 1 LECTURE II. _Of the Properties of all Matter_ 9 _Of Aeriform Substances_ 13 LECTURE III. _Of Atmospherical Air_ 15 LECTURE IV. _Of Dephlogisticated Air_ 18 _Of Phlogisticated Air_ 20 LECTURE V. _Of Inflammable Air_ 21 LECTURE VI. _Of Nitrous Air_ 23 LECTURE VII. _Of Fixed Air_ 27 _Of Hepatic Air_ 29 _Of Phosphoric Air_ 30 LECTURE VIII. _Of Dephlogisticated Marine Acid Air_ 31 _Of Phlogisticated Marine Acid Air_ 32 LECTURE IX. _Of Vitriolic Acid Air_ 34 _Of Fluor Acid Air_ 36 LECTURE X. _Of Alkaline Air_ 37 _Miscellaneous Observations relating to Air_ 38 LECTURE XI. _Of Liquid Substances; and first of Water_ 41 LECTURE XII. _Of the Nitrous Acid_ 45 LECTURE XIII. _Of the Vitriolic Acid_ 49 _Of the Marine Acid_ 52 LECTURE XIV. _Of the Vegetable Acids, and others of a less perfect nature_ 54 LECTURE XV. _Of the Phosphoric Acid_ 59 LECTURE XVI. _Of Alkalis_ 62 LECTURE XVII. _Of Liquid Inflammable Substances_ 66 _Of AEther_ 68 LECTURE XVIII. _Of Oil_ 70