Page:Popular Science Monthly Volume 50.djvu/352

336 the geological construction of the region makes it very probable that a disruption of the Austral tract took place before that of the South American.

Prof. Scott, in a review of the relationship of the southern land masses (Science, February 28, 1896), thus states his position: "In conclusion, it may be observed that the facts of paleontology may best be explained on the assumption that the antarctic land mass has at one time or another been connected with Africa, Australia, and South America, which formerly radiated from the south pole as North America and Eurasia now do from the north pole. While this seems a highly probable assumption, much remains to be done before the history of the southern continents is as well known as that of the northern ones, and in particular many questions must remain open until the Tertiary mammals of Africa and Australia shall have been recovered."

This evidence from paleontology may thus be taken to strongly supplement that which comes from the side of pure geology—evidence indicating a much further extension southward of the South American continent, and of a former union between it and a past and still partially existing Antarctica.



EN or twelve years ago even the most advanced physicians were not agreed that consumption belonged to the communicable diseases, and practically none took any steps to prevent its spread from the sick to the well. In fact, there were not a few who denied that it was ever contracted in this way. Heredity, physical conformation, atmospheric and soil conditions were regarded as the important factors, and all efforts were directed to the study and control of these. To-day there is an entire change of position. Communicability stands first in importance, and there are few who deny that it is the essential factor in the perpetuation of the disease. The most strenuous efforts now being made against its ravages are based on the belief that the greatest menace to the well is the presence of the sick.

Tuberculosis—of which, as will be explained more fully below, consumption is a variety—now appears at the head of the list of contagious diseases published weekly by the New York Board of Health, and means have been taken to have all cases in the city reported and instructed. Circulars containing directions for preventing contagion by disinfection of sputa have been placed in the hands of physicians for distribution, and many, if not all. 