Page:Popular Science Monthly Volume 20.djvu/879

Rh of the tree; this form, Mr. Higley believes, as the final result of his investigations so far, to be at least a part of and probably the whole cause of the disease. The affection is, of course, transmitted by whatever will convey the fungus or its spores. Mr. Higley has no faith in any of the cures that have been proposed for the yellows, and believes that where they have seemed to be successful, not yellows, but some other cause of trouble was present. The only remedy he can propose is to root out the tree and burn every part.

The Approaching Transit of Venus.—An international conference respecting the observations of the transit of Venus, which will take place next December, was held in Paris last October, under the presidency of M. J. B. Dumas. Most of the European countries, Brazil, Chili, and the Argentine Republic, were represented, and reported upon the observing stations which would be cared for by their respective countries. France will establish eight stations, Brazil five, Germany four, Denmark and the Netherlands, Austria, Hungary, Chili, and Mexico one each, Spain and the Argentine Republic two each, forming a line of stations from the southern part of the United States through Central America, the West Indies, and the east and west coasts of South America to the Strait of Magellan. Besides these, Great Britain will have sixteen stations arranged in groups of two, with principal centers of observation at the Cape of Good Hope, in Australia, New Zealand, and the Antilles; and Portugal will have two stations within its proper limits, and one at Benguela or Lorenço Marquez. No reports were made from Italy and the United States. A committee to which the subject was referred made a report concerning the best arrangements for details of observation; and a resolution was adopted in favor of calling, after the return of the observing expeditions, an "International Commission on the Transits of Venus," in which each state should be represented by a plenipotentiary, to form a provisional organization for collecting all the data of the observations, and deducing from them in common a general determination of the parallax of the sun.

Sewage in Oysters.—The oysters of Dublin Bay arc threatened with extinction in consequence of the turning of the sewage of the city into the water. Edible fish were numerous a generation ago in the river Liffey, which is the chief carrier of sewage to the bay, but now they are rarely seen there. Oysters were taken for examination, by Dr. Charles A. Cameron, from a spot which is covered by about ten feet of water at high tide, but is nearly dry at low water. The brine of a large proportion of them emitted a slight but distinctly fetid odor, and when examined microscopically was found to swarm with micrococci and other low organisms of sewage. Of samples of sea-water taken at the beds at high tide and from little pools containing oysters at low water, the latter contained ten times as much albuminoid ammonia and thirty times as much saline ammonia as the former, proving that it was in great part composed of sewage. It is impossible for the oysters to keep from imbibing much of this water; and if we sometimes acquire the germs of fever from drinking water and milk, why may we not also from the juice of oysters raised in sewage-polluted waters?

Malarial Organisms.—M. A. Laveran has found, in the blood of patients suffering from malarial poisoning, parasitic organisms, very definite in form and most remarkable in character; motionless, cylindrical curved bodies, transparent and of delicate outlines, curved at the extremities; transparent spherical forms provided with fine filaments in rapid movement, which he believes to be animalcules; and spherical or irregular bodies, which appeared to be the "cadaverie" stage of these, all marked with pigment-granules. He has also detected peculiar conditions in the blood itself. During the year that has passed since he first discovered these elements, M. Laveran has examined the blood in one hundred and ninety-two patients affected with various symptoms of malarial disease, and has found the organisms in one hundred and eighty of them, and he has convinced himself by numerous and repeated observations that they are not found in the blood of persons suffering from diseases that are not of malarial origin. In general, the