GARV1N 



3435 



GAS 



Charles Garvice, 

 British novelist 



Russell 



Other Verses, and in 1875 pub- 

 lished a three - volume novel, 

 Maurice Durant. Between 1890- 

 1900 his stories, mainly charac- 



,,,:, - :,,,- .,,,,:. ,,, -.,,., t G T 1 S C (1 1) V 



healthy senti- 

 ment, roman- 

 tic h a p p e n- 

 ings, and hap- 

 py endings, be- 

 gan to be wide- 

 ly popular in 

 America. Sim- 

 ilar success 

 came to him in 

 England later, 

 and he wrote a 

 long succession of novels on con- 

 ventionalised lines. They included 

 Just a Girl, 1899 ; Her Heart's De- 

 sire, 1900; The Outcast of the 

 Family, 1901 ; In Cupid's Chains, 

 1903; Love Decides, 1904; The 

 Gold in the Gutter, 1907 ; The One 

 Girl in the World, 1916. He died 

 at Richmond, March 1 . 1920. 



Garvin, JAMES Louis (b. 1868). 

 British journalist. While in his 

 teens he made his first contribu- 

 tion to journal- _ _|_ _ 

 ism in The ft j 

 Eastern Morn- 

 i n g News, 

 Hull. Corre- 

 spondent of 

 United Ireland 

 in 1890, he was 

 leader writer 

 on The New- 

 castle Chroni- 

 cle, 1891-99 ; 

 joined the staff 

 of The Daily 

 Telegraph in 1899 ; edited The Out- 

 look, 1905-6; The Pall Mall Gazette, 

 1912-15 ; and became editor of The 

 Observer in 1908. President of the 

 Institute of Journalists, 1917-18, 

 he is known as a writer and speaker 

 on foreign and fiscal topics, and 

 as a student of German history, 

 literature, and economics. 



Gary. City of Indiana, U.S.A., 

 hi Lake co. At the head of Lake 

 Michigan, 30 m. S.E. of Chicago, it 

 is served by the Lake Shore and 

 Michigan Southern and other rlys. 

 The city owes its prosperity to the 

 United States Steel Corporation, 

 which in 1906 selected it as the site 

 for the establishment of its chief 

 works. The corporation owns most 

 of the land on which the city 

 stands, and also controls the elec- 

 tricity, gas, water, and other public 

 utility undertakings. Gary is the 

 greatest steel -producing city in the 

 world, and has important tin-plate 

 and bridge-building works, foun- 

 dries, locomotive and car shops, 

 and cement and tube factories. 

 The chief buildings are the city hall, 

 the public library, and two hos- 

 pitals. Pop. 16,800. 



Hainct 



GAS: ITS NATURE AND USES 



A. J. Liverseclge and Capt. E. de W. S. Colver 



A number of articles deal with the subject of gas. It is first defined 

 from the theoretical point of view. A section follows on gas 

 in mines. Gas in warfare is the subject of a separate article, 

 and then follow a number of entries dealing with this matter, e.g. 

 Gas Helmet ; Gas Poisoning. See also Gas Company ; Gas Engine ; 

 Gas Manufacture 



Gas or vapour is matter in a 

 perfectly fluid state. Sir Oliver 

 Lodge differentiated solids, liquids, 

 and gases in the statement : "A 

 solid has volume and shape ; a 

 liquid has volume, but no shape ; a 

 gas has neither volume nor shape." 



Oxygen, hydrogen, and nitrogen 

 are common gases. Both solids and 

 liquids may change into gas by the 

 application of heat, as gases may 

 be transformed into liquids and 

 solids by cold. Certain gases, e.g. 

 hydrogen and oxygen, were once 

 termed " permanent gases " on the 

 assumption that they were not 

 liquefiable, an assumption no 

 longer true. The distinction be- 

 tween a gas and a vapour that may 

 be drawn is that the latter is more 

 readily made liquid by a small de- 

 crease of temperature or pressure. 

 Boyle, Dalton, Charles 



The study of the properties of 

 gases and the laws which govern 

 them is one which has laid the 

 very foundations of chemistry, and 

 has advanced modern physics 

 in an incalculable degree. The 

 general laws governing gases are 

 simple, and are as follows : 



Boyle's Law, enunciated by 

 Robert Boyle in 1662, states that if 

 the temperature of a gas be kept 

 constant its volume changes in a 

 definite way as the pressure 

 changes ; if the pressure P is 

 doubled the volume V is halved, 

 and so on. This, an experimental 

 law, is not strictly accurate, es- 

 pecially under high pressures. 



Dalton's Law is dxie to John 

 Dalton, who in 1801 began to pub- 

 lish his series of important papers 

 on the properties of gases, and he 

 enunciated the fact that if a 

 number of gases are contained in 

 the same vessel they mix homo- 

 geneously, and that the pressure on 

 the sides of the containing vessel is 

 the sum of the pressures of each of 

 the gases. 



Charles's Law deals with the 

 effect of temperature on the volume 

 of a gas. Charles, Dalton, and Gay- 

 Lussac at about the same time dis- 

 covered that if the pressure is kept 

 constant the volume of a gas in- 

 creases according to the law v=v l 

 (\-\-kt) where v is the volume at 

 t C. v l5 that at C. and k is a con- 

 stant. The importance of the law 

 is that k is the same for all gases, 

 1/273. This law again is not strictly 

 accurate, for if it were it would lead 

 to the result that at 273 C. a gas 



would cease to have volume. At very 

 low temperatures the law changes, 

 but enough investigations have 

 not been carried out to say ex- 

 actly in what way. 



LAWS OF DIFFUSION. Since a 

 gas tends to fill its container, if two 

 containing vessels filled with gases 

 are joined together the two will 

 mix. The rate of mixing, or diffu- 

 sion, depends upon their relative 

 densities. The law of diffusion 

 states that the rate is inversely 

 proportional to the square root of 

 the relative densities. Because of 

 this property of diffusion the pro- 

 portion of nitrogen and oxygen in 

 the air, for example, is the same 

 in England as Australia, on the 

 sea coast as on the top of a moun- 

 tain. The different sensation air 

 gives in different places is due to 

 temperature, water content, etc., 

 and not to any variation in com- 

 position of its main gases. When a 

 gas is allowed to escape through a 

 small hole it is said to effuse. The 

 rate of effusion varies as diffusion, 

 and this fact has been made use of 

 to discover the density of one gas 

 in terms of another. 



Avogadro's Law states that in 

 equal volumes of different gases at 

 the same pressure and temperature 

 there are an equal number of 

 molecules. 



Absorption and Solubility 



Solids have the property of con- 

 densing gases in a thin film on their 

 surfaces and of absorbing or oc- 

 cluding them. Palladium, for ex- 

 ample, under certain conditions 

 will absorb 900 times its own 

 volume of hydrogen ; coconut 

 charcoal 170 times its own volume 

 of ammonia. Gases are easily 

 soluble in many liquids, the quan- 

 tity being dissolved being pro- 

 portional to the pressure. Gases 

 absorb light in different ways and 

 have consequently absorption 

 bands in the spectrum. They are 

 poor conductors of heat, and as 

 conductors of electricity vary ac- 

 cording to their temperature, 

 pressure, etc. Air, for example, is 

 a conductor at normal pressures, 

 and an insulator at low pressures. 

 , In the kinetic theory of gases 

 it is assumed that the molecules 

 of a gas are in constant motion 

 along "straight lines ; during such 

 motion they impinge upon other 

 molecules, gaseous, liquid, or 

 solid, and suffer a change of direc- 

 tion and an alteration of speed. 



