Page:Popular Science Monthly Volume 22.djvu/513

Rh passage of the air during the formation of the crater. The edges of Copernicus, Archimedes, and several other lunar craters are marked by analogous features.

"A formation like a dike appears to rise in the center of a considerable number of craters on the moon. I have been able to produce something analogous to this also, a representation of which is visible in Fig. 2. After I had ceased blowing in air, a last bubble was formed, which uplifted the mass, but could not project it above the edge of the crater. The lunar dikes are very probably formed in this way, by the action of the gas, at the end of the active period of the craters."



HERE is no subject of so much general interest as this, concerning which there is, at the same time, such a widely prevalent ignorance. There are few, especially among women, upon whom will not devolve, at some time in their lives, the care of the sick; fewer still who will not at some time become dependent upon such care; and it might naturally be supposed that matters of such primary and universal importance as sanitary conditions and the practical application in the sick-room of scientific principles would be too familiar to every one to need to be further enlarged upon. But the fact is, it too frequently happens that all the scientific knowledge which ever enters the sick-room comes in with the doctor and goes out again with him.

This state of things requires to be improved. Knowledge, and that correct knowledge we call science, is just as indispensable to the nurse as to anybody else. It is a great mistake to suppose that all women—even all good women—make good nurses. The best intentions and the tenderest heart may coexist with an utter lack of executive ability, and be more than counterbalanced by ignorance and prejudice. Native aptitude gives advantage, but it can not be relied upon alone. Even those who possess in the highest degree the natural gift of ministration which renders them so acceptable to the invalid would find their power of usefulness very largely increased by a familiarity with what may be properly called the science of the sick-room. Physicians are recognizing more and more the importance of hygienic agencies in the treatment of disease, and with this there has come an increasingly urgent call for the scientific instruction and practical training of those who are to take charge of invalids. Science explains the conditions upon which the art of the nurse depends, and lays down principles which can not be violated without injury; but it is not at all necessary to make a parade of technical language in stating its 