858 



THE POPULAR SCIENCE MONTHLY. 



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 appa- 

 ratus and all expenses of a qualified opera- 

 tor, at any convenient place in the neigh- 

 borhood 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 tha't 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 remark- 

 able 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. ta- 

 tula. The alkaloids of black and white helle- 

 bore, too, are innocuous to the rodents. Pro- 

 fessor 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 Solanaccw without 

 detriment, and that the rat bears very well 

 the addition of these vegetables to its or- 

 dinary food. The immunity of the rabbit 

 and Guinea-pig is so great that M. Heckel 

 Mas been able to bring up several genera- 

 tions 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. 



Opinm-Eating and Intemperance. It is 



asserted by Dr. Moffat that one result of 

 the early closing of public-houses in Eng- 

 land 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 " intem- 

 perance " and the growth of opium-consump- 



tion. Dr. Moffat in 1874 first became im- 

 pressed with the belief that the consumption 

 of opium was more general among the work- 

 ing 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 in- 

 creased from a very small quantity to two 

 quarts per week. Similar reports were re- 

 ceived from druggists in other mining vil- 

 lages. 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, co- 

 logne-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 Popnlation. In ll Peter- 

 mann's Mittheilungen " the population of the 

 globe is estimated, for 18*77, 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 fe- 

 males; 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, 



