Page:Popular Science Monthly Volume 50.djvu/297

Rh other directions than that on which it is most intently bent. So much for "excess" in bicycling; for devotion to the machine for itself; for "scorching." But of moderate use of the machine, of its employment as an aid to other exercises and recreations, MM. Tissier and Du Pasquier would probably have, certainly ought to have, quite other views.

Cement as a Fire-proof Covering.—Mr. J. S. Dobie has recently published the results of a number of tests showing the effect of heat on cements. Tests were made upon pure briquettes and briquettes made up of sand and cement in various proportions. The briquettes were heated in a small assay furnace. The first thing noticed on removal from the furnace was a loss of weight, and the pure cement briquettes almost invariably showed extensive cracks. The loss in weight is due to the driving out of the water of crystallization, hardened cement consisting of hydrated crystals of aluminum and calcium silicate. After removal from the furnace, the briquettes were subjected to various tests, and in every case where the water of crystallization had been approximately all driven off the briquettes were unable to resist any load whatever. A high temperature was not necessary to destroy the strength of the cement. The lowest heat which could be generated by the furnace, considerably below red heat, was found to be as destructive as the highest temperature. The conclusions arrived at by Mr. Dobie were: 1. That while there is no doubt that a covering of Portland cement concrete will afford some protection to a metal column or girder, still there appears to be no doubt that the concrete itself will be ruined by the action of the fire, and will have to be removed as soon as the fire is subdued. 2. The concrete covering, if heated, will not stand the action of water. In a case of fire, when the hose is turned on, the water strikes the cement covering, probably red hot, and immediately cracks it off, leaving the ironwork bare. 3. In calculating for the design of the columns and girders, and especially for floors, no allowance should be made for the strength of the concrete, and the cement covering should be considered as so much extra load on the system. 4. That in a fireproof building floors should never be constructed of slabs of cement forming short spans or arches from girder to girder, without any support, and that these experiments indicate that the value of concrete as a fire-protecting material has been greatly overestimated, and that disastrous results may follow, from confidence in a building protected with such material.

Chinese Medicine.—The medicine of the Chinese is described by M. Paul d'Enjoy as being more serious, more widely extended, and further removed from superstitious practices than that of the other cognate peoples of the far East. The doctors concoct and sell their remedies, as well as prescribe them, provide themselves with luxurious shops, and use all the tricks of the trade to make their parcels attractive. Many of their remedies are administered in large, badly tasting pills, only slightly mollified in their flavor by licorice. These pills are inclosed in capsules of wax as large as pigeons' eggs, which preserve the compound from contact with the air, and are broken when the remedy is taken. Special preparations are sent out from the large shops of the principal commercial centers. Among the most popular of the specialties are the little brick-red cholera pills, composed of mangosteen bark and various tropical essences, such as santal, eaglewood, and calumba. The Dau-nhu-y is a medicinal oil which produces excellent effects in headaches, and generally incases of brain weariness of every kind. It is rubbed on the temples, and is inhaled by strong breathing, after having been rubbed upon the nostrils. Relief is obtained through the cold which its evaporation quickly produces. The basis of the preparation is camphor; and, as a whole, its effect may be compared to that of the headache pencils familiar in our drug stores. Chinese medicine is chiefly based on plants, and is taught in books which are often very ancient. In his practice the doctor strictly follows the methods of the master by whom he has been taught. With a very grave face, his eyes protected by large spectacles of thick glass, the old physician feels the pulse of his patient, and never fails to make him show his tongue. Next he examines his eyes, and asks a series of questions, the answers to which will help him out in his diagnosis. Then he writes his prescription