lire 

 rich 



416 OBSERVATIONS IN CHEMISTRY AND MINERALOGY. 



X. The same bundle, in which all the wires are now adhering to each other 

 as if they were welded is again exposed as before. Oxidation lasts 15 minutes 

 using the compressed air. Duration of heat in hydrogen two hours ; temperat 

 610° C. Loss of weight is 0.001 gram; but the development of ruby 

 especially near the cords, as shown in figure 7, Plate XXXVI. There is little 

 dust copper. The direction of copper particles is chiefly downward. Is it be- 

 cause against the iron support the temperature is highest? 



XL Same bundle was oxidized without compressed air. The tube was simply 

 inclined, whereby a light current of air was induced. Duration of heat 1 h. 10 m., 

 temperature as before. There is slight show of ruby color in the lee of the 

 forward asbestos cord. But some of the wires wear a roughness which means 

 that the oxyd film has started peeling. Start heat again at one o'clock and 

 keep up till 4 h. 30 m. Temp, steady at 600°-605° C. Loss in weight of bundle 

 0.0011, of which 0.0002 fell off in form of spangles, hence volatilized 0.0009 gram. 

 Tube shows a patch of copper dust at A and slight ruby marks at B and C 

 (fig. 8, Plate XXXVI) . All this was visible after the first hour. The 2]/ 2 hours 

 of second heat brought no change. 



XII and XIII are enduring tests of 4 hours and 2 hours each at same tempera- 

 ture with same bundle. Loss in XII is 0.0002 gr., in XIII 0.0001 and there are 

 traces of red in each case. Since this is limit of sensitiveness of balance, it must 



also be the limit of the experiment. 



Conclusion from these Experiments —{a) In order that ruby glass may form 

 from the volatilization of copper ions in metallic copper, the latter must contain oxy- 

 gen throughout its mass. 



(b) The action is a maximum at the start. 



(c) The lowest temperature is about 600° C. 



XIV. A new bundle was made up of Quincy copper, sample 2. Wire rubbed 

 and burnished with charcoal. Weight of bundle 22.9210. The tube is Med 

 with hydrogen before turning on the flames. Duration of heat is 2 hours at 

 temperature of 650°-670° C. The loss in weight is 0.0065 gram. The ruby- 

 glass is well developed but different in relative location from any of the previou 

 experiments. There is a broad, bright ruby band across tte f orwar d ™» 

 of the bundle at A , reaching in fact ahead of the copper against the nydroge 

 current. At the rear terminal B the band is less intensely colored, is narrow 

 and does not reach beyond the ends of the wires. Between the cords, 

 there is a very pale film of copper-dust (fig. 9. Plate XXXVI.) ^ 



XV. This is to be simply a question of loss in weight, wltl L sam< r of heat 

 same heat but in a new tube. Hydrogen current is lively. Durat f 



3 hours. Loss is nil and there is no trace of red visible on the glass-tuo • 



XVI. A repetition of XV. Duration 1 hour 50 minutes. Loss m ^^ 

 is 0.0015. No coloration on glass. Total loss by heating in nyoru& 



6 hours is 0.008 gr. or 0.035 per cent 





XVII 



3.008 gr. or U.UcJo per cent. _ . 15 mmU tes 



Same bundle oxidized in nearly horizontal position during 



