experiment, instead of calling me and other students of astronomy by bad names. To encourage him further, I will undertake to pay the hire of suitable photographic apparatus and all expenses of a qualified operator, at any convenient place in the neighborhood of the Bedford level, if any one of the negatives should show the three boats (at distances, say, of one mile, three miles, and five miles from the camera) at the same, or anything near the same, level. Mr. Hampden will observe that I reply to his questions by simply denying that the facts are such as he alleges, and by showing a convenient way in which this matter may be put to the test, once for all."
Poison-Proof Animals.—The action of the solanaceous alkaloids on the rodents has been investigated by Professor Heckel, of Marseilles, with a view of ascertaining the conditions which determine the remarkable immunity which those animals enjoy against poisoning by the substances named. Not only the rabbit and the pig, but rats can with impunity take belladonna, and the alkaloids of Datura stramonium and D. tatula. The alkaloids of black and white hellebore, too, are innocuous to the rodents. Professor Heekel's researches show that the rabbit and Guinea-pig may be fed for a long time with the leaves and even with the roots of the poisonous Solanaceæ without detriment, and that the rat bears very well the addition of these vegetables to its ordinary food. The immunity of the rabbit and Guinea-pig is so great that M. Heckel Mas been able to bring up several generations on this food, giving them during the summer the leaves exclusively, and during the winter mixing dried powdered leaves and roots with equal parts of other food. It is his opinion that the effect of poisons lessens in proportion as animals recede in organization from man.
Opium-Eating and Intemperance.—It is asserted by Dr. Moffat that one result of the early closing of public-houses in England is an increased consumption of opium and laudanum. It would be an interesting subject of inquiry to ascertain what is the exact ratio between the decline of "intemperance" and the growth of opium-consumption. Dr. Moffat in 1874 first became impressed with the belief that the consumption of opium was more general among the working classes than was commonly supposed; and set to work to ascertain the truth. The druggist in a certain mining village informed him that since the public-houses were closed at 10 p. m., his sales of laudanum have increased from a very small quantity to two quarts per week. Similar reports were received from druggists in other mining villages. Nor is it only in opium and chloral hydrate that there is increased consumption. There are many soporifics and stimulants taken in place of beer, viz., absinthe, cologne-water, tincture of rhubarb, mixture of opium and chloroform, chlorodyne, and the ethers. In Ireland there has been a great increase in the quantity of sulphuric ether consumed since the public houses in that country were closed on Sundays.
Statistics of Population.—In "Petermann's Mittheilungen" the population of the globe is estimated, for 1877, at 1,429,145,000 souls, occupying a superficial area of 134,460,000 square kilometres. Inhabitants are distributed among the continents as follows: in Europe, 312,398,480; in Asia, 813,000,000; in Africa, 205,219,500; in Australia and its islands, 4,411,300; in America, 86,116,000. Between 1875 and 1877 the whole population increased by 42,000,000. This increase, however, does not depend on the very great excess of births over deaths, but is the result of more accurate enumeration, and more extended knowledge of various localities. The populations of European countries, in 1877, were: Belgium, 5,336,185; Holland, 3,865,456; England, 34,242,966; Italy, 27,769,475; Germany, 42,727,360; France, 36,905,788; Switzerland, 2,759,854; Austria, 37,350,000; Denmark, 1,905,000; Spain, 16,526,511; Portugal, 4,057,538; Greece, 1,457,894; European Turkey (exclusive of the tributary states), 9,573,000; European Russia, 72,392,927; Sweden and Norway, 6,237,268. As regards the proportion of the sexes, there were to 1,000 men in the Canary Islands 1,208 females; in Sweden, 1,064; Switzerland, 1,045; England, 1,043; Germany, 1,037; Austria, 1,024; Russia, 1,022; Spain, 1,016; France, 1,007; Italy, 989; Belgium, 985; Greece,
