Sir William Ramsay, of University College, London, will deliver the first of a series of six Lowell Institute lectures on "The Discovery of the Gases of the Atmosphere" this evening at 8 o'clock. The lectures will be free and will be given in Huntington Hall, 491 Boylston street, Boston, on Monday and Thursday evenings at 8 o'clock. The subject for this evening is "The Early History of the Atmosphere."

Subjects of Other Lectures.

The dates and titles for the remaining lectures are:

October 24.--"Lavoisier's Revolution."

October 28.--"The Properties of Argon."

October 31 and November 4.--"Discovery and Properties of Helium, Neon, Krypton, Oxenon."