Page:Popular Science Monthly Volume 9.djvu/666

640 seeds had become attached to the core when under water, and had afterward germinated when the core was stored.

in an address on the "Relations of Ophthalmology to General Surgery," takes the ground that, while the growth of specialism in this department has given us improved operations and more dexterous operators, it has retarded investigation by diminishing the number of laborers in the field, and the opportunities of those laborers to study the facts from the standpoint of general pathology.

Italian chemist, A. Casali, obtains a green pigment by calcining an intimate mixture of one part of bichromate of potash and three parts of baked gypsum, of the variety known as scagliola. The result is a grass-green mass which, on boiling with water, or mixing with dilute hydrochloric acid, leaves a fine powder of an intense green.

recommends the use of the microscope in determining the mineral contents of potable water. On evaporating a few drops on a plate of glass, it is easy to distinguish carbonate and sulphate of lime and of magnesia, chloride of sodium, and nitrate of potash and of soda. C. Bischof further recommends the use of the same instrument for determining the organic substances contained in water.

has been recently devised for supplying London with an inflammable mixture of gases to replace coal. The new gas, "pyrogen," as it is called, is a mixture of nitrogen and carbonic oxide, three-fourths by weight consisting of the latter gas. The combustion temperature of pyrogen is stated to be 2,700° Cent., and for heating-purposes the flame of the burning gas is to be allowed to raise some good radiating substance to incandesence in an ordinary grate.

of Elbeuf, having observed that in epidemics of foot-and-mouth disease no beast affected with cow-pox is ever stricken with the former disorder, vaccinated thirty oxen, and not one of the twenty-five beasts effectually vaccinated showed any sign of foot-and-mouth disease, even after living for months among animals largely affected with it.

is opposed to the project of assimilating the American dollar to the English pound sterling; he advocates, rather, assimilation to the five-franc piece. The partial accession of the United States to the franc system would, he says, immensely increase the motives for the English to accept it also, thus preparing the way for an international coinage.

the purpose of photographing solar eclipses, Mr. Brothers, of the Royal Astronomical Society of London, suggests that at least three achromatic lenses of five or six feet focal length, corrected for the actinic rays, should be constructed, with all suitable apparatus, to be in readiness for use when required. The light of the corona, he adds, is sufficiently actinic to produce good pictures when an instrument of long focus is used—it is only a question of time in the exposure and accuracy in the adjustment of the driving-clock apparatus attached to the equatorial mounting.

cruelty-to-animals bill, now under consideration in the British Parliament, provides that vivisection should only be performed with a view to the advancement of human knowledge, the prolongation of human life, or the alleviation of human suffering; that it must take place in a registered laboratory; that it must be performed by a person duly licensed; that the animals must be put under the influence of anæsthetics; and that, where pain would be prolonged after the anæsthetic effects had subsided, the animals should be killed.

their last report, the Commissioners in Lunacy in England discourage the practice, which has grown to be quite general, of filling up the asylums with idiots, imbeciles, and eccentric or troublesome paupers, to the exclusion of the really insane, who need and are entitled to the skill, care, and attention, that asylums are intended to afford.

Commission Supérieure of the Paris Exposition of 1878 has decided upon the general plan of the enterprise, and estimated the probable receipts. The expense is set down at 35,000,000 francs, and the receipts at 19,000,000; difference, 16,000,000 francs. To meet this deficit, the city of Paris will contribute 6,000,000 francs, and the state 10,000,000 francs. The buildings for the exposition will be erected in the Champ de Mars and in the Trocadero—localities situated on opposite banks of the river Seine. At first, it was proposed to widen temporarily the bridge known as Pont d'Iéna, but soon another project was entertained—that of erecting a new bridge forty metres in width. The question is yet under deliberation.

the petroleum-mines of Alsace the miners test their safety-lamps in the following manner before going down the pits: At the bottom of an open jar is placed a small quantity of petroleum-spirit, the vapor of which, mingling with the air in the jar, forms an explosive mixture. The lamp is plunged into this mixture, and the slightest, defect in the lamp is proved by an explosion.