﻿Intelligence and Miscellaneous Articles. 247 



(1 ) That in our apparatus we could not have a perfectly uniform 

 temperature; 



(2) That we did not make certain of dealing with perfectly pure 

 liquids and entirely deprived of air. 



As to the uniformity of the temperature, Signor Galitzine has 

 already replied, in the April number of the Philosophical Magazine, 

 that the criticism regarding him was not well founded. 



I can now repeat the same ; for I must remind the reader that 

 for heating I used petroleum distilled at determined temperatures, 

 the vapours of which circulated in a stove with double sides, in the 

 interior of which a closed glass globe contained the tubes. The 

 length of these was a little more than the fourth part of the length 

 of the entire globe, and they were placed in the middle of it, in 

 correspondence with the height of the mouth of the tubes which 

 conducted the petroleum-vapour into the stove. 



I have already noted that an even temperature was preserved in 

 the stove up to exactly -^ degree for teu or fifteen minutes before- 

 hand, and sometimes even for a longer period ; thus it is abso- 

 lutely impossible to suppose that tht-re was not a uniform tem- 

 perature in the globe, and especially in the small space occupied 

 by the little tubes. 



As regards the absolute purity of the liquids and the entire 

 absence of air, one cannot perhaps give a categorical reply ; from 

 all the memoirs on the subject, however, it would appear the 

 greatest care was taken to that end by every experimentalist. 



But admitting that the apparent difference depends on the 

 impurity of the substance or on the presence of air, still one could 

 not altogether impugn the conclusion at which we have arrived. 



In fact one could not explain merely by the hypothesis of 

 Andrews the fact described in § 7 of my first memoir (Nuovo 

 Cimento Genn. for Feb. 1893), namely, that in two bulbs placed in a 

 stove at the same height, and connected by a small capillary tube 

 in the form of a j^, one of which contains liquid ether and not the 

 other, when they become heated above the critical temperature, 

 and then slowly cool, the characteristic cloudiness appears only in 

 the bulb which originally contained the liquid. Nor, according to 

 the same hypothesis, would the conduct of the isocores in regard 

 to the critical temperature be as it is in reality, as I demonstrated 

 in § 10 of the same memoir. 



Finally, the fact observed by Galitzine (Wied. Ann. vol. 50. p. 541) 

 is in contradiction to the ideas of Messrs. Eamsay and Young, 

 namely, that if the two branches of a tube are separated at the IT 

 by a little column of mercury, and the one branch is filled entirely 

 with ether and the other partially, when the tube becomes heated 

 above the critical temperature the movement of the column of 

 mercury from the first branch towards the second does not cease, 

 even if the temperature is increased to 209°-5 C. 



I was proving the same thing when Galitzine's paper appeared, 

 using for this purpose a straight tube instead of a curved one, and 



