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THE POPULAR SCIENCE MONTHLY 



gas, by the simple action of water on calcium 

 carbide has been mentioned in the Monthly. 

 Great possibilities from the use of this 

 method are foreshadowed by Prof. Vivian 

 B. Lewes. The property possessed by calcic 

 carbide of forming acetylene with water was 

 accidentally discovered while working with 

 the electric furnace to form an alloy of cal- 

 cium. A mixture containing lime and pow- 

 dered anthracite was fused down to a semi- 

 metallic mass, which, proving not to be 

 desired, was thrown into a bucket contain- 

 ing water, when a rapid effervescence took 

 place, and the escaping gas burned, on the 

 application of a light, with a smoky but 

 luminous flame. This source of light can 

 be produced by the exposure to the electric 

 furnace of finely ground chalk or lime mixed 

 with powdered carbon in any form. When 

 the calcic carbide is placed in a glass flask 

 and water is allowed slowly to drip upon it 

 from a dropping tube, the decomposition 

 begins at once with considerable rapidity, 

 and the acetylene pours off in a continuous 

 stream ; as the decomposition continues, the 

 solid mass in the flask swells up and is 

 eventually converted into a mass of slacked 

 lime. The value of this useful product may 

 be deducted in computing the cost of the 

 acetylene. For commercial purposes the 

 carbide may be cast direct from the electric 

 furnace into rods or cylindrical cartridges, 

 which, when twelve inches long and an inch 

 and a quarter in diameter, will weigh one 

 pound and will give five cubic feet of gas. 

 Acetylene is a clear, colorless gas, with an 

 intensely penetrating odor which somewhat 

 resembles garlic. The strong smell is a 

 great safeguard in its use, and, when the 

 quantity of the gas is dangerous, can not be 

 endured. Hence, while poisonous like car- 

 bon monoxide, its use, on account of its 

 odor, is much more safe. When burned it 

 emits a light greater than that given by any 

 known gas, its illuminating power, calculated 

 to a consumption of five cubic feet an hour, 

 being two hundred and forty candles. It 

 being liquefiable with comparative ease, 

 enormous volumes of it may be compressed 

 in small wrought- iron or steel cylinders, in 

 which it may be stored and from them 

 burned as wanted. It should not be used 

 with silver or copper, as it forms explosive 

 compounds with their aimnoniacal solutions. 



Advantage may be taken of the calcic car- 

 bide method of forming acetylene by putting 

 sticks of the carbide coated with a slowly 

 soluble glaze into cylinders containing water 

 and attached to portable lamps. As the 

 glaze dissolves from the surface of the stick 

 of carbide, acetylene is generated, and the 

 five cubic feet furnished by the stick are 

 compressed by their own pressure, so as to 

 supply through a suitable burner a light of 

 more than twenty candles for about ten 

 hours. The most immediate use contem- 

 plated by Prof. Lewes for acetylene is for 

 enriching ordinary illuminating gas. 



Cycling and the Heart. Dr. B. W. Rich- 

 ardson represents cycling as differing from 

 other exercises in that it tells primarily and 

 most distinctly upon the heart. It produces 

 at once a quickened circulation, though the 

 riders may not be conscious of it ; and this 

 accounts for the astonishing journeys a cy- 

 clist can undertake, and his endurance as 

 against sleep. Although the heart increases 

 in action and sometimes undergoes enlarge- 

 ment, the author has never seen a rider 

 embarrassed by overstrain of it, faintness, 

 breathlessness, angina, or vertigo, so as to 

 oblige him to dismount. Indeed, he had 

 known a practiced rider who could climb 

 a hill on his machine, but could not mount a 

 flight of stairs on his feet without breath- 

 lessness and a slight palpitation ; he had 

 never seen a sudden death from cycling. He 

 had met with instances in which, after sev- 

 eral years of cycling, there was evidence of 

 heart disease, with general languor and in- 

 ability to sustain fatigue if exercise were 

 again tried on the machine ; and, on the 

 other hand, he had known examples in which 

 even an octogenarian had kept up the exer- 

 cise in a moderate degree apparently with 

 benefit to the circulation. He had seen in 

 some cases apparent benefit arising from cy- 

 cling even where there was an indication of 

 some disease affecting the circulation, and 

 had known good to arise from it in cases of 

 varicose veins and of fatty degeneration, and 

 in conditions of anaemia. In other cases ex- 

 cessive cycling had been a definite cause of 

 injury to the circulation. The author be- 

 lieves that cycling in moderation may be per- 

 mitted and even recommended to persons 

 with healthy hearts ; that it is not necessary 



