Sect. III. Of DEPHLOGISTICATED Air, and of the conftitution of the Atmosphere 29 Sect. IV. A more particular account of fome Proceffes for the Production of dephlogisticated Air 62 Sect. VI. Of Air procured from various Subftances by means of Heat only 104 Sect. VII. Of Air produced by the Solution of Vegetable Substances in Spirit of Nitre 121 Sect. Sect. 1. The Preface to the Directions as first published Sect. 2. The Directions The Preparation PART ibid. 279 280 281 283 III. Of Dr. NOOTH's Objections to the preceding Method of impregnating Water with Fixed Air, and a Comparison of it with his own Method, both as published by himself, and as improved by Mr. PARKER 293 Sect. XVI. An Account of fome Mifreprefentations of the Author's Sentiments, and of fome Differences of Opinion with respect to the Subject of Air 304 Sect. XVII. Experiments relating to fome of the preceding Sections, made fince they were printed off THE APPENDIX. Number I. Experiments and Obfervations relating to fome of the Chemical Properties of the Fluid, commonly called FIXED AIR; and tending to prove, that it is merely the Vapour of a particular Acid. In Two Letters to the Rev. Dr. PRIESTLEY. By WILLIAM BEWLY. 337 Numb. Numb. II. A Letter from Dr. PERCIVAL, F. R. S. and S. A. to the Rev. Dr. PRIESTLEY, on the Solution of Stones of the Urinary and of the Gall Bladder, by Water impregnated with FIXED AIR 360 Numb. III. A Letter from Dr. DOBSON of Liverpool, to Dr. PRIESTLEY 368 Numb. IV. Extract of a Letter from JOHN WARREN, M. D. of Taunton, to Dr. PRIESTLEY, with a medical Cafe, proving the Use of Glyfters of FIXED AIR in a putrid Difeafe 370 THE THE INTRODUCTION, CONTAINING An Account of an additional APPARATUS for experiments on Air, and of the precautions proper to be attended to in the use of it. HA AVING made fome improvements in my apparatus, for making experiments on different kinds of air, it will be moft convenient, in pursuance of the method which I took in the firft volume of these observations, to give a fhort account of the feveral parts of it, previous to my entering upon the detail of the experiments themselves; and likewise to be a little more particular in the account of fome things of this nature, which I thought it unneceffary to dwell upon before, but which I now find it would have been useful to many persons, if I had explained more fully at that time. I must acknowledge, however, that, with respect to many things, which those who are altogether unused to experiments of this kind complain that they did not understand, till they faw me perform the operations in their prefence, |