All vessels that carry blood to the heart, are called veins. All vessels that carry blood from the heart, are called arteries.
Transpiration is a term often used generically, to signify the passage of fluids or gases through membranes, internally or externally; but perspiration is a specific term, signifying transpiration on to the external surface.
As a substitute for a jar with a stop-cock, take a piece of lead pipe bent in the form of a siphon, and insert it in the mouth of a reversed jar. This experiment is as conclusive whether the air is inhaled once only or breathed many times.
Mr. Frederick Emerson, of Boston, has devised a simple and effective apparatus for removing vitiated air from a room. It is successfully used upon all the public school-houses of Boston. It is now being generally applied to the school-houses and other public buildings, as well as private dwellings, of New England.
Dr. Wyman’s valuable work on “Ventilation,” and the work of Henry Barnard, Esq., on “School-house architecture,” can be advantageously consulted, as they give the practical methods of ventilating and warming shops, school-rooms, dwelling-houses, public halls, &c.