Two letters from a physician in London, to a gentleman at Bath. [electronic resource] : The first containing, such plain and easy rules as will preserve health, and prevent all Diseases until extreme old Age; together with some Observations on the present Use of Tobacco, and the particular Effects of it upon the human Body enquired into. The second, an earnest dissuasive from the use of empiricks, wherein from the Insufficiency of Experience, without a learned Education, is clearly proved, that the Practice of all such is generally confused, and consequently very dangerous; and the several Reasons urged for employing them particularly answered. Published at the particular Request of some Friends, for the universal Benefit of Mankind.