Chemistry and Physics. 379 



gible limit of the red rays to the ultra-violet above wave-length 

 3240. The authors have identified all the lines and bands repre- 

 sented, and by this means have proved the presence of the rare 

 element gallium in the Bessemer metal and in the roasted ore 

 from which it was extracted. Careful analyses showed that the 

 gallium was concentrated in the iron. The lines 4171*6 and 4032-7 

 (on Rowland's scale) were repeatedly obs^'rved in the spectrum 

 of the Bessemer flame, again in that of the " mixer " metal and 

 in the residue or precipitates separated from it, and finally in that 

 of the residues obtained upon treatment of the roasted Cleveland 

 ore itself. — Proc. Roy. Soc, Ix, 35. 



3. Flame tewperalures. — W. J. Waggener has made a detailed 

 study of the Bunsen flame with the aid of thermo-couples of 

 platinum and a 10-per-cent platinum-rhodium alloy. In most 

 cases the wires of the couple were taken straight through the 

 flame, with the junction nearest the center. The conductivity and 

 the E.M.F. of the flame were found to be without influence upon 

 the galvanometer currents. But in every case the wires had to 

 be quickly removed from the flame after taking a readinor^ as 

 their thermal E.M.F.'s suflTered a gradual alteration in the flame. 

 In the outer mantle of the flame the temperatures indicated by 

 most of the thermo-couples ranged from 1500° to 1700° C, accord- 

 ing to the height above the base of the flame. The hottest point 

 was at a height of 2^"" ; the total height of the flame being lO*^"^. 

 The coldest part of the flame, about 1400° C, was found near the 

 top of the blue inner mantle. In all the observations, the con- 

 duction of heat along the wire reduced the temperature of the 

 junction and vitiated the results. The hottest part of the flame, 

 in the outer mantle, was 1724° C, as indicated by the thinnest of 

 the wires (0-05™™ diameter). Taking the increase of tempera- 

 ture with the reduction of diameter, and plotting a curve, the 

 latter is found to cut the axis of no thickness at a point corre- 

 sponding to about 1770°, which may therefore be taken as very 

 approximately the true value of the highest temperature of the 

 Bunsen flame. — Wied. Ann., Iviii, 579 ; JProc. Phys. Soc.^ xiv, 

 315. 



4. Liquefaction of Helium. — K. Olszewski having been pre- 

 sented by Professor Ramsay with 140^°°^ of helium, endeavored 

 to liquefy it with the apparatus which he has used in his re- 

 searches on oxygen and hydrogen.* The results were negative. 

 Helium appears to be more permanent than hydrogen. The 

 quantity of gas employed, however, was too small to afiord 

 definite conclusions. Olszewski believes that his experimental 

 results show the single atom constitution of helium. The relation 

 of this one atom constitution to the difficulty of liquefaction is 

 even more marked in the case of helium than in that of argon. 

 In consequence of its permanence of constitution helium affords a 

 valuable means of determining temperatures beyond the boiling 



* Further details in regard to these experiments were given in the October num- 

 ber, p. 301. 



Am. Jour. Sci. — Fourth Series, Yol. II, No. 11. — November, 1896. 

 27 



