Page:Science vol. 5.djvu/287

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��man go Tern men t. 1°. Experimeiits on Jiving animals must only be performed in serious investigations, or for purposes of Instruction. 2°. in public lectures such experiments must not be performed, unless Ihey are necessary for the lull elucidation iif the subject. 8°. The preparations, as a rule, must be made before the lectures Iwgin, and not in the preierice o( the audience. 4°. The experiments must only be per- formed by quallBed professors, or by their assistants on their responsibility. 5°. Experiments which will be equally satisfactory if performed on the lower specleA of auitnnls must not be performed on the higher K pec les. 6", In all cases where theexperiraeiit can he performed without inconvenience under anaesthetics, anaesthellcs must be ad mini lie red.

— Nature states, that, in a paper read before the Statistical society on Feb. IT, Sir Richanl Temple endeavored to check the various official returns of the population of China hj applying the results ob- tained from the population statistics of Brlti-ih 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 la^l century and a half varying between tJfl.OOO.UOO and -■163,000,000. These returns, as Professor Douglas pointed out, varied with the purjwscs for which the enumerations were made. China proper, anuIation loved U> 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 1S4 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 computations, he found, that, over a total area of l,500,UoO square miles, the population, according to this estimate from the Indian avenige*. would be 282,101,928, or, lay, 183 peraons to the square mile, while the latest official returns obuined from China show 349.&S.i,3S6, or 227 inhabitants to the square mile. The general conclusion, he said, might be thiit the latest Chinese returns, though probably in excels of the reality, did not seem to be eitrjvagant or Incredible, on the whole, if tested by the known averages of the Indian

— Lebasteur has Invented an Ingenious process for determining the tblcknesa of iron plates in boilers, or places where they cannot othertrUe be measured without cutting them, which process is described in Le i/^nJe chlL He spreads upon the plate the thick- ness of which he deslri'S to Bud, and also upon a piece of sheet-Iron of known thicknesa. a layer of tallow about a hundre<lth 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 consequetitly 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 oil New Guinea by the former Dutch resident at Temate, Mr. Van Braam-Uorris is an- nounced. The work la to he edited by Mr. Knbldfe Van der Aa, who Is himself an authority on the sub- ject, and will be accompanied by a map. Mr. Van Braam-Morrls succeeded iu penetrating considerably to the south during an official tour on the Ambemo or Rochuasen rivers.

— At the February meeting of tlie Russian geo- graphical society. Gen. Meyer read a paper on the transcaspian province, Merv, or Akhal-Tfik^. 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 Pollakotf, who was present at the meeting, and the further progress of Putaiiin, who has traversed Ordoz, the country in the great l>ead of tlie 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 m^netic observations has been intrusted to Ur. Traut- ve tier, formerly director of the Pavlovsk observatory.

— Arrangements arc iti progrcsi lor a collection of life specimens of tropical fishes at the Indian and colonial exhibition of I8H6. Thisscheme wlllinvolve the erection o( tanks for the maintenance of water at far higher temperature than that suitable for fishes of the temperate zone,

— The largest block of atumlmim 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 liichca and a half on each side of the base, but weighs wily one hundred ounces. The surface la 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. Kn'jinferiTv), 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 ns the difFlculties In the way of the in- troduction of electric lights into dwelling-houses are removed, the gas companies will be forced to reduce

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