Page:Popular Science Monthly Volume 7.djvu/787

Rh sensitive than silver bromide to all the less refrangible rays, and also to white light; 3. That the sensitiveness of the bromide to the green rays is materially increased by the presence of free silver nitrate; 4. That bromide and iodide of silver together are more sensitive to both the green and the red rays (and probably to all the rays) than either the bromide or the iodide separately; 5. That, contrary to Becquerel's theory, there do not exist any rays with a special exciting or a special continuing power, but that all the colored rays are capable both of commencing and continuing the impression on silver iodide and bromide.



Acclimatization Society of Cincinnati has had printed muslin handbills offering a reward of ten dollars for "any information that will convict persons of violating" in the vicinity of that city "the laws framed for the protecting of birds."

Prussian Government offers a prize of 3,000 marks (about $700) for a method which will give plaster-casts the power of resisting periodically repeated washings, without injuring in the least the delicacy of the form, or the tint of the plaster. Also a prize of 10,000 marks (about $2,500) for a material for making plaster-casts of art-works, possessing the advantages of plaster, but which, without any special preparation, will not deteriorate by periodically-repeated washings. The conditions of competition are stated in full in the Journal of the Society of Arts, No. 1,177.

official returns published in the Sanitarian, it appears that in the city of Boston there occurred, in the year 1874, 11,717 births, whereof 6,021 were of males and 5,696 of females. The proportion is as one to 28.27 of population. Of the whole number 54.74 per cent, were of foreign parentage by both parents; 66.35 per cent, had foreign-born fathers; 73 per cent, were of parents one or both of whom were foreign-born. Of Irish parentage there was one birth to 20.05 of the population; of native, one to 73.24.

is the name of the first Hindoo that ever dissected a human cadaver; this he did in 1836. Still not till seventeen years later did scientific medicine begin to find favor among the natives of India. At present students in great numbers attend the medical colleges of Calcutta, Madras, Bombay, Agra, and the schools of Lahore and Nagpoor.

the whole month of June, according to the Monthly Weather Report, vessels navigating the North Atlantic were in danger from ice-drift and icebergs. The steamship Scandinavian, while off the coast of Newfoundland, on the 29th of June, sighted no less than 100 icebergs, many of them of monstrous size.

whose book, "Wanderings in New Guinea," is almost universally considered to be a work of fiction, on June 22d read a paper at the London Anthropological Institute on "The Papuans of New Guinea." Before the paper was read several members urged the chairman to require of the author some evidence of his good faith, but the motion was over-ruled, and Captain Lawson was allowed to proceed. In the discussion which followed. Dr. Busk and others expressed opinions adverse to the author's credibility, and the usual vote of thanks was not passed.

Tribune, of Salt Lake City, announces the discovery in North Mill Creek Canon, near the line of the Utah Central Railroad, of a rich mine of mica. The belt is said to be about 1,000 feet wide and 1,000 feet long. Sheets of mica three by four inches can be obtained in abundance, and development of the mines will doubtless open beds from which sheets of any size can be taken.

in Zanzibar states that in that country ants are a great pest. They move along the roads in masses so dense that beasts of burden refuse to step among them. If a traveler should fail to see them coming in time to make his escape, he soon finds them swarming about his person. Sometimes, too, they ascend the trees and drop on the wayfarer.

telegraphic cable between Anglesea and Ireland was recently taken up for the purpose of repairing a fault which had occurred not far from the former island. The fault was found to have been caused by a minute crustacean (Limnoria terebrans), which had pierced the gutta-percha covering of the cable. The application of creosote seems to be the only preventive of the depredations of this little creature.

story is published in the English newspapers, of the discovery in Syria of a large number of villages, the names of which are unknown to the geographer, and even to the tax-gatherer. No fewer than seventy-nine of these hapless hamlets, so the story runs, have been unearthed in the single district of Damascus, besides about an equal number in other parts of the province, by Medjeddin Effendi, who has been devoting his time and energies to the exploration of old official 