March 27, 18S5. 



SCIENCE. 



263 



man government. 1°. Experiments on living animals 

 must only be performed in serious investigations, 

 or for purposes of instruction. 2°. In public lectures 

 such experiments must not be performed, unless they 

 are necessary for the full elucidation of the subject. 

 3°. The preparations, as a rule, must be made before 

 the lectures begin, and not in the presence of the 

 audience. 4°. The experiments must only be per- 

 formed by qualified professors, or by their assistants 

 on their responsibility. 5°. Experiments which will 

 be equally satisfactory if performed on the lower 

 species of animals must not be performed on the 

 higher species. 6°. In all cases where the experiment 

 can be performed without inconvenience under 

 anaesthetics, anaesthetics must be administered. 



— Nature states, that, in a paper read before the 

 Statistical society on Feb. 17, Sir Richard Temple 

 endeavored to check the various official returns of 

 the population of China by applying the results ob- 

 tained from the population statistics of British India. 

 The various statements made by the Chinese govern- 

 ment as to the numbers of people under its rule show 

 violent fluctuations, those of the last century and 

 a half varying between 436,000,000 and 363,000,000. 

 These returns, as Professor Douglas pointed out, 

 varied with the purposes for which the enumerations 

 were made. China proper, and India, said Sir Rich- 

 ard Temple, have about the same area, — a million 

 and a half of square miles. Both countries are under 

 similar conditions, physical, technical, climatic, geo- 

 graphical. In both there is a strong tendency to 

 multiplication of the race. In both the population 

 loved to congregate in favored districts, to settle 

 down and multiply there till the land could scarcely 

 sustain the growing multitudes, and to leave the less 

 favored districts with a scanty though hardy popula- 

 tion. The average population of the whole of India 

 is 184 to the square mile, and, if this average be ap- 

 plied to China (exclusive of the central plateau), it 

 gives a population of 282,191,600 souls. The writer 

 then compared, one by one, the eighteen provinces 

 of China proper with the districts in India corre- 

 sponding nearly in physical characteristics and cul- 

 tivable area; and, summarizing these compulations, 

 he found, that, over a total area of 1,500,650 square 

 miles, the population, according to this estimate from 

 the Indian averages, would be 282,161,923, or, say, 

 183 persons to the square mile, while the latest official 

 returns obtained from China show 349,885,386, or 

 227 inhabitants to the square mile. The general 

 conclusion, he said, might be that the latest Chinese 

 returns, though probably in excess of the reality, did 

 not seem to be extravagant or incredible, on the 

 whole, if tested by the known averages of the Indian 

 census. 



— Lebasteur has invented an ingenious process 

 for determining the thickness of iron plates in boilers, 

 or places where they cannot otherwise be measured 

 without cutting them, which process is described in 

 Le fjenie civil. He spreads upon the plate the thick- 

 ness of which he desires to find, and also upon a 

 piece of sheet-iron of known thickness, a layer of 

 tallow about a hundredth of an inch thick. He 



then applies to each, for the same length of time, a 

 small object, such as a surgeon's cauterizing instru- 

 ment, heated as nearly as possible to a constant tem- 

 perature. The tallow melts: and as in the thicker 

 plate the heat of the cautery is conducted away more 

 rapidly, while in the thin plate the heat is less freely 

 conducted away, and the tallow is consequently 

 melted over a larger area, the diameters of the circles 

 of bare metal around the heated point, bounded 

 after cooling by a little ridge of tallow, will be to 

 each other inversely as the thickness of the plates. 

 The process is stated to have given, in the inventor's 

 hands, results of great accuracy. 



— The approaching publication in Holland of a 

 Dutch work on New Guinea by the former Dutch 

 resident at Ternate, Mr. Van Braam-Morris, is an- 

 nounced. The work is to be edited by Mr. Robidee 

 Van der Aa, who is himself an authority on the sub- 

 ject, and will be accompanied by a map. Mr. Van 

 Braam-Morris succeeded in penetrating considerably 

 to the south during an official tour on the Amberno 

 or Rochussen rivers. 



— At the February meeting of the Russian geo- 

 graphical society, Gen. Meyer read a paper on the 

 transcaspian province, Merv, or Akhal-Teke. The 

 paper did not mention any new facts, but dwelt on the 

 barrenness of the country, and on its poor resources 

 for trade, etc. The secretary mentioned the return 

 of Poliakoff, who was present at the meeting, and the 

 further progress of Potanin, who has traversed Ordoz, 

 the country in the great bend of the Yellow River, 

 China, and has found numerous ruins which testify 

 that the country was formerly occupied by an agricul- 

 tural people. The discussion of the Novaia Zemlia 

 magnetic observations has been intrusted to Mr. Traut- 

 vetter, formerly director of the Pavlovsk observatory. 



— Arrangements are in progress for a collection of 

 live specimens of tropical fishes at the Indian and 

 colonial exhibition of 1886. This scheme will involve 

 the erection of tanks for the maintenance of water at 

 far higher temperature than that suitable for fishes 

 of the temperate zone. 



— The largest block of aluminum ever cast is made 

 from American ore, and forms the apex of the Wash- 

 ington monument. It is nine inches and a half high, 

 and measures five inches and a half on each side of 

 the base, but weighs only one hundred ounces. The 

 surface is whiter than silver, and is so highly polished 

 that it reflects like a plate-glass mirror. 



— There has recently been considerable agitation 

 in Germany upon the smoke question ; and some have 

 suggested that government interfere, and establish 

 'stoker schools,' through which the stokers of all 

 manufactories shall be obliged to pass before receiv- 

 ing a position. Besides this, it is urged that these 

 manufactories be obliged to build high chimneys. 

 Engineering, in a recent number, very sensibly re- 

 marks that such a system would be absurd, and fur- 

 ther adds that there is no necessity for such action, 

 for, as soon as the difficulties in the way of the in- 

 troduction of electric lights into dwelling-houses are 

 removed, the gas companies will be forced to reduce 



