The vitality of the hydrogen flame in foul air, Prof. Clowes points out, makes it useful for maintaining the flame of a miner's safety lamp in an impure atmosphere. The author's testing lamp, which burns either oil or hydrogen, or both together, can be carried into foul air with both substances burning. The oil flame is extinguished as soon as the proportion of carbonic acid reaches a certain limit, while the hydrogen continues to bum. As soon as the miner goes back into a somewhat purer atmosphere, the still burning hydrogen relights the oil flame, and the miner is not left in complete darkness, as he otherwise would be.
The Earth's School of Enterprise.—In his study of the Relation of the Earth to the Industries of Mankind, Prof. O. T. Mason infers that the earth was in the beginning and is now the teacher of the activities through which commodities are conducted through the progress of industries. "There were quarriers, miners, lumberers, gleaners, and some say planters; there were fishermen, fowlers, trappers, and hunters before there was a genus homo. There were also manufacturers in clay, in textiles, and in animal substances before there were potters, weavers, and furriers; there were all sorts of moving material and carrying passengers and engineering of the simplest sort. It might be presumption to hint that there existed a sort of barter, but the exchange of care and food for the honeyed secretions of the body going on between the ants and the Aphidæ looks very much like it. The world is so full of technological processes brought about among her lower kingdoms that I should weary you in enumerating them. Stone-breaking, flaking, clipping, boring, and abrading have been going on always, by sand-blast, by water, by fire, by frost, by gravitation. Archæologists tell us that savages are very shrewd in selecting bowlders and other pieces of stone that have been blocked out and nearly finished by Nature for their axes, hammers, and other tools. In tropical regions of both hemispheres where scanty clothing is needed, certain species of trees weave their inner bark into an excellent cloth, the climax of which is the celebrated tapa of Polynesia. Furthermore, the fruits of vines and trees offer their hard outer shells for vessels and for other domestic purposes, and as motives in art and handicraft. Among the animals there is hardly one that has not obtruded itself into the imaginations of men and stimulated the inventive faculty. The bears were the first cave dwellers; the beavers are old-time lumberers; the foxes excavated earth before there were men; the squirrels hid away food for the future, and so did many birds; and these were also excellent architects and nest-builders; the hawks taught men to catch fish; the spiders and caterpillars to spin! the hornet to make paper, and the crayfish to work in clay."
A Generation of French Science.—The Revue Scientifique, of Paris, last November entered upon its thirty-third year. Noticing the event, it recalled the fact that when it was begun, in 1863, the Darwinian theory was only timidly sustained by a few, while it was contested by most men of science—in France at least. The Revue fought actively for it from the first, and for ten years gave it the most prominent place among subjects discussed. After that it gave other questions, including the new ones as they sprang up, a larger share of attention. The purpose which the Revue has constantly pursued has been to keep scientific readers acquainted with the work accomplished by other students in related or neighboring fields, and thereby serve as a kind of bond of connection between the scattered members of the scientific body. The collected volumes, according to the Revue's own expression, constitute a kind of gigantic scientific encyclopædia, in which may be found the traces of great scientific contests mingled with dogmatic expositions of the most glorious contemporary discoveries.
Sewer-fed Oysters.—Concerning the possible contamination of oysters by sewage, which seems to be demonstrated by experiences at Middletown, Conn., Nature says: "It has been alleged, on the evidence of certain recent bacteriological investigations as regards the contents of London sewers, that the organism producing typhoid fever can not live and multiply in sewers. But the organism has been found in sewers; it also lives in sea-water; and the fact remains that sewage bathes our oysters during cultivation
