Experimental essays on medical and philosophical subjects : particularly, I. On the fermentation of alimentary mixtures, and digestion of the food. II. On the nature and properties of fixed air. III. On the respective powers, and manner of acting, of the different kinds of antiseptics. IV. On the scurvy, with a proposal for trying new methods to prevent or cure the same, at sea. V. On the dissolvent power of quick-lime, and a further investigation of the properties of fixed air