Gentlemen, In addressing a Letter to so distinguished and so important a part of the community, it becomes me to say, that, I am not myself a man of experimental Science, neither, out of the ordinary occupations of my past life, have I ever seen a scientific experiment made in any one department of Chemistry, or Natural Philosophy; all that I know, with the above exception, has been acquired by reading and meditation. My present address is chiefly confined to those Philosophers, who study and pr