POPULAR MISCELLANY. 



427 



uties, setting forth the mischievous effects 

 of excessive strain upon the nervous system 

 of scholars, and asking that an end be put 

 to an abuse which " threatens, Uttle by ht- 

 tle, to reduce the cultivated classes of so- 

 ciety to a state of moral weakness that shall 

 render them incapable of great and manly 

 resolution." 



Effects of Tobacco on Youth.— Dr. G. 



Decaisne has made special observations of 

 the effects of tobacco in thirty-eight youths, 

 from nine to fifteen years old, who were ad- 

 dicted to smoking. With twenty-two of the 

 boys there was a distinct disturbance of the 

 circulation, with palpitation of the heart, 

 deficiencies of digestion, sluggishness of the 

 intellect, and a craving for alcoholic stimu- 

 lants; in thirteen instances the pulse was 

 intermittent. Analysis of the blood showed, 

 in eight cases, a notable falling off in the 

 normal number of red corpuscles. Twelve 

 boys suffered frequently from bleeding of 

 the nose. Ten complained of agitated sleep 

 and constant nightmare. Four boys had 

 ulcerated mouths, and one of them contract- 

 ed consumption, the effect. Dr. Decaisne be- 

 lieved, of the great deterioration of the 

 blood, produced by the prolonged and ex- 

 cessive use of tobacco. The younger chil- 

 dren showed the more marked symptoms, and 

 the better-fed children were those that suf- 

 fered least. Eleven of the boys had smoked 

 for six months ; eight, for one year ; and 

 sixteen, for more than two years. Out of 

 eleven boys who were induced to cease smok- 

 ing, six were completely restored to normal 

 health after six months, while the others 

 continued to suffer shghtly for a year. 



Danger from Overhead Wires. — Profess- 

 or Sylvanus P. Thompson mentions as one 

 of the most solid objections to overhead 

 wires, that they are a permanent and ab- 

 solute source of danger, because every wire 

 of whatever kind deteriorates more or less 

 slowly under atmospheric influences, espe- 

 cially in the smoky, sulphur-laden air of 

 cities. Those best qualified from long ex- 

 perience to speak on the subject agree that 

 the life of every wire is limited, and no one 

 can tell how or when it will snap. The fact 

 has been established by Professor Hughes 

 that every vibration imparted to a wire 



brings it a stage nearer to a state of inter- 

 nal crystallization, when, its fibrous struct- 

 ure having become completely degenerated, 

 it snaps short. He has measured the num- 

 ber of vibrations which determine the length 

 of life of wires of different kinds, and finds 

 it to be varying according to the material, 

 but limited in every case. " Given at first a 

 wire of ideal perfection, when it has swayed 

 to and fro its allotted number of hundreds of 

 thousands of times in the breezes, it must 

 snap. But no such wire is attainable ; all 

 are more or less faulty, and can not be re- 

 lied on, even with the most diligent inspec- 

 tion, when once set up in the smoky air." 

 Numerous accidents, according to Mr. Preece, 

 have arisen from the falling of wires, and a 

 case is on record where an omnibus-driver 

 was decapitated from such a cause. 



Atmospheric Action on Sandstone. — M. 



E. Wadsworth, of Cambridge, records cer- 

 tain observations on St. Peter's and Pots- 

 dam sandstones, made several years ago near 

 Mazomanie, Wisconsin. The St. Peter's 

 sandstone is composed almost wholly of a 

 pure quartz sand, and in the outliers of it, 

 found on the hill-tops south of the town, the 

 parts covered by the soil were more or less 

 friable, and the grains distinct ; while the ex- 

 posed portions of the same blocks and slabs 

 were greatly indurated, the grains being al- 

 most obliterated, and the rock possessed the 

 conchoidal fracture and other characteristics 

 of a quartzite. In the autumn of 1872 a block 

 of clear white Potsdam sandstone was found, 

 the protected side of which was friable, while 

 the other sides, especially the one most ex- 

 posed to the prevaihng storms, was nearly a 

 quartzite. This block was only about two feet 

 square, and, as a test of the correctness of 

 the above conclusion, the indurated surface 

 was broken off, and a comparatively friable 

 surface exposed. This locality was visited 

 the following spring, when the fresh surface 

 was found much indurated, and approached 

 toward a quartzite. 



Phosphoric Glass and its Applications. 



— At a recent meeting of the French Acade- 

 my of Sciences, a number of articles were 

 presented for inspection that were made of 

 a glass composed simply of phosphate of 

 lime. The new application is the invention 



