ISI 



< HKMISTRY. 



crmtion. be looked upon an one of the mat key- 

 StoMt of ti organic edifica. With a cheap mid 

 easy method of prtpar h as seams to be 



afforded by the calcium-carbide process, it >s 

 hardly possible to forsssa the result* hi. 



mattly produced. Tha most valuable ap- 

 ptfaatiott of acetylene promises to be to purposes 

 of illumination, for which it has many advan- 

 u*r over coal gas. It has been shown by ex- 

 pertinent that it i* twelve times as efficient in 

 producing light as the bast fas now in use for 

 thai pun--*, a consumption of 5 cubic feet per 

 bourTurnishing a light of 250 candle power, 

 while an equal amount of common gas will give 

 a light of only SO candle power. Further, only 

 about one sixth as much oxygen is consumed as 

 in obtaining an equal amount of light by the 

 UK**! methods. The gas is poisonous when 

 brtwthr.1. but its presence may be readily de- 

 tct*l by it* characteristic heavy odor of garlic. 



w and very convenient method of prepar- 

 ing the unsaturated hydrocarbon allylene. <',|| 4 . 

 by means of the action of magnesium on the 



of the alcohols is described by iw. 

 v -- M & Braid. Ths moan ha* 



iployed with methyl and ethyl and other 

 but with none of them is the gas so 

 pure as that derived from the use of propyl 

 alcohoL When this substance is used the new 

 method is said to be far preferable to the ordi- 

 nary one of decomposing propylen bromide with 



rVrsulpnuric acid and its anhydride were first 

 obtained and described by M. Bcrthalot, and its 

 potassium, ammonium, and barium salts were 

 prepared in 1891 by Dr. Marshall, of Kdinburgh. 

 A second memoir by M. Berthelot on the acid 

 - salts confirms Dr. Marshall's results, and 

 includes a description of the met ho, i of prepar- 

 ing the acid by electrolysis of a solution in dilute 

 sulphuric acid of potassium or ammonium sul- 

 phate, accordingly as the potassium or ammo- 

 nium salt i- required, in the inner cell, and dilute 

 sulphuric acid in the outer cell. At the expira- 

 tion of fifteen or twenty hours, the inner cell 

 will contain large quantities of beautiful crystals 

 of the persulphate. Crystals of the salt are also 

 obtained by direct electrolysis of sulphuric 

 add and subsequent addition to the product ..f 

 a concentrated solution of potassium bi-ulphai.-: 

 and bv the gradual addit ion of anhydrous t wrium 

 peroxide to concentrated sulphuric acid. Potas- 

 sium persulphate attacks mercury at ordinary 

 temperatures, with production of a yellow basic 

 saipnato that appears to be identical with the 

 It called for/l mineral. 



ilr vTe!rhta.-Bohuslav Brauner's latest 

 aalenlartons of the atomic weight of tellurium 

 givt the number 127-71. which i* higher by 0*86 

 than the atomic weight ,,f *! where- 



as, from ita position in the periodic system, tel- 

 lurium should have an atomic weight between 

 Wand IK. On this account the author is led 

 to the conclusion that it is not a simple sub- 

 stance, which is supported by the following con- 

 siderations : 1. tellurium precipitated and dried 

 in a current of an inert gas gives higher value 

 for the atomic weight than when sublimed in 

 hydrogen : 2. the properties and composition of 

 the dlommide : 3. the varving results obtained 

 on attempting the synthesis of the dioxide, the 



basic sulphate, an<l certain metallic telluridcs; 

 4, the behavior "f tellim-us and tellurie acid 

 solutions toward hydrogen sulphide. 



The atnn< \\.-I-M <>f tuiip*teii has been re- 

 1'. Smith, of tin- fniv.-rsity of 

 IN-nnsyl\an n^ <>f 'J series of experi- 



ments* iM-rformed by 2 a>sistunts. Tin- in. an 

 value lie rived from the first series, of 9 ex- 

 I- nment-. was 184*92, taking oxygen as 0*16; 

 and from the second series of 6 experiment^ 

 184*70. The highest and lowest values obtained 

 in the first series differed only 0-02, and in the 

 second series only 0*07 from the mean. Strik- 

 ing the medium between these two means gives 

 184*8 as a close approximation to the true atomic 

 ' of tungsten. This value is con^idrrabl> 

 higher than the currently accepted one, 184*03, 

 the nuinlN-r afforded by Clarke and Beck* ! 

 calculation of the results of older ill-termina- 

 tions. The increase is probably due to the great 

 pains which were taken to remove the traces of 

 molybilrnmn from the tungstic acid used in the 

 experiments. 



That nickel and cobalt should have the same 

 at i .m ir weight, as they have appeared to have f r> >m 

 past analyses, seems at variance with Men : 

 law, and many efforts have been made to se- 

 cure greater accuracy in the e-ti mat ions. I'n.f. 

 \V inkier has recently made analyses of cobalt by 

 methods which he declares were quite unim- 

 peachable, and publishes as the results of two 

 series, each consisting of several individual de- 

 terminations, carried on with an interval of some 

 months. and with metals from independent min- 

 eral deposits Ni = 58*72, and Co = 59*37, when 

 II = 1 and I = 126-38. This gives cobalt an 

 atomic weight at least half a unit higher than 

 that of nickel. 



The value, 87*70, for the atomic weight of 

 Mrontium. found by Pelouze in 1845, has been 

 confirmed byT. W. "Richards. IVloii/.e's method 

 was found on a comparison of anhydrous stron- 

 tium, chloride, and silver. Richards used an- 

 hydrous strontium bromide and silver, and took 

 the results of 3 sets of analyses carried on by dif- 

 ferent methods. 



Chemical Analysis. Numerous analyses of 

 sea water show that while salinity, or the amount 

 of dissolved salts contained in 100 parts of 

 the water, varies greatly in different regions of 

 the ocean, the composition of the dissolved salts 

 or the ratio of the constituents of sea salts- 

 remains practically the same in all the super- 

 ficial marine waters. Consequently, it is only 

 necessary to determine the i -hlorine in a given 

 weight of water to ascertain at once the respec- 

 tive quantities of other salts present in the sam- 

 ple. It appears, however, from Dittmar's exam- 

 ination of the "Challenger" waters, that lime is 

 slightly more abundant in samples of sea water 

 collected in greater depths than in samples col- 

 lected nearer th*- surface of the ocean. Some evi- 

 dence apnears too of slight differences in the 

 it ion .f the sea salts. There is also abun- 

 idenee that changes in chemical compo- 

 sition take nl ace in the substances deposited on 

 f the ocean ; and with the view of 

 throwing some light on the manner in which 

 these changes are brought about, Dr. John .Mur- 

 ray and Robert Irvine have examined the com- 

 position of the water associated with marine de- 



