flow of fresh water. This inflow is called endosmosis, and the outflow of the solution is called exosmosis. If an India-rubber bottle be filled with water and immersed in alcohol or ether, the endosmosis of the spirit will be so powerfully exerted as to distend the bottle considerably. If the bottle be filled with alcohol or ether and surrounded by water, it will nearly empty itself.
The force exerted by this action is displayed by the rising of the sap from the rootlets of a forest giant to the cells of its topmost leaves. Not only plants, but animals also, are complex osmotic machines. There is scarcely any vital function—if any at all—in which this osmosis does not play an important part. I have no doubt that the mental effort I am at this moment exerting is largely dependent upon the endosmosis and exosmosis that is proceeding through the delicate membranes of some of the many miles of blood-vessels that ramify throughout the gray matter of my brain. But I must wander no further beyond the kitchen, having already said enough to indicate that exosmosis is fundamental to the philosophy of beef-tea extraction, and reserve further particulars for my next paper.
Postscript.—I feel bound to step aside from the proper subject of these papers to make public acknowledgment of an act of honorable generosity, especially as many hard things have been said concerning American plagiarism of the work of British authors. As everybody knows, we have no legal rights in America, and any publisher there may appropriate as much of our work as he chooses. American legislators are responsible for this. Nevertheless, I received, a short time since, a letter from Mr. E. L. Youmans, of New York, inclosing a check for £20, as an honorarium, in consideration of the fact that these papers are being reprinted in "The Popular Science Monthly." Shortly before this, a similar remittance was sent from another publishing firm (Messrs. Funk & Wagnalls), who have reprinted "Science in Short Chapters." These facts indicate that some American publishers have larger organs of conscientiousness than the present majority of American legislators.
I am told that another American publisher has issued another reprint of "Chemistry of Cookery" without making any remittance; but, as Mr. Proctor would say, "this is a detail."—Knowledge.
By Dr. TH. BODIN.
ALTHOUGH the world no longer believes in the gods, demi-gods, and heroes with which the ancients and our pagan ancestors animated nearly every object, old-country people still retain a considerable relic of heathenism in the shape of myths of a host of spirits of