Sect. VIII. _Of the effect of the CALCINATION of METALS, and of the EFFLUVIA of PAINT made with WHITE-LEAD and OIL, on AIR_ 133 Sect. IX. _Of MARINE ACID AIR_ 143 Sect. X. _Miscellaneous Observations_ 154 PART II. _Experiments and Observations made in the Year 1773, and the Beginning of 1774._ Sect. I. _Observations on ALKALINE AIR_ 163 Sect. II. _Of COMMON AIR diminished, and made noxious by various processes_ 177 Sect. III. _Of NITROUS AIR_ 203 Sect. IV. _Of MARINE ACID AIR_ 229 Sect. V. _Of INFLAMMABLE AIR_ 242 Sect. VI. _Of FIXED AIR_ 248 Sect. VII. MISCELLANEOUS EXPERIMENTS 252 Sect. VIII. _QUERIES, SPECULATIONS, and HINTS_ 258 THE APPENDIX. Number I. _EXPERIMENTS made by Mr. Hey to prove that there is no OIL of VITRIOL in water impregnated with FIXED AIR_ 288 Number II. _A Letter from Mr. HEY to Dr. PRIESTLEY, concerning the effects of fixed Air applied by way of Clyster_ 292 Number III. _Observations on the MEDICINAL USES of FIXED AIR. By THOMAS PERCIVAL, M. D. Fellow of the ROYAL SOCIETY, and of the SOCIETY of ANTIQUARIES in LONDON_ 300 Number IV. _Extract of a Letter from WILLIAM FALCONER, M. D. of BATH_ 314 Number V. _Extract of a Letter from Mr. WILLIAM BEWLEY, of GREAT MASSINGHAM, NORFOLK_ 317 Num. VI. _A Letter from Dr. FRANKLIN_ 321 Number VII. _Extract of Letter from Mr. HENRY of MANCHESTER_ 323 THE INTRODUCTION. SECTION I. _A general view of PRECEDING DISCOVERIES relating to air._ For the better understanding of the experiments and observations on different kinds of air contained in this treatise, it will be useful to those who are not acquainted with the history of this branch of natural philosophy, to be informed of those facts which had been discovered by others, before I turned my thoughts to the subject; which suggested, and by the help of which I was enabled to pursue, my inquiries. Let it be observed, however, that I do not profess to recite in this place _all_ that had been discovered concerning air, but only those discoveries the knowledge of which is necessary, in order to understand what I have done myself; so that any person who is only acquainted with the general principles of natural philosophy, may be able to read this treatise, and, with proper attention, to understand every part of it.