TIIE LAST OF THE GASES. 



465 



and void." The latter, on the same grounds, sub- 

 stituted for the article written by one of their 

 most distinguished contributors for the first edi- 

 tion of their Dictionary another in the precisely 

 opposite sense. 



My crime, in Mr. Wallace's eyes, is that I 

 stated that the subject of clairvoyance was " first 

 thoroughly sifted " by those later investigations 

 on which the Academy itself relied ; and that I 



passed by(l) the earlier report, which was never 

 adopted by the Academy, and was finally rejected 

 by it as worthless ; and (2) the article of M 

 Rostan, which was for the same reason ejected 

 from the Dictionary for which it had been writ- 

 ten. I appeal from his judgment to that of the 

 readers of the Athcnceum. 



William B. Carpenter. 

 — Athencmm. 



THE LAST OF THE GASES. 



THE year 1817 will ever be memorable in the 

 history of scientific progress, its close hav- 

 ing been marked by a brilliant series of researches 

 which have ended in an absolute demonstration 

 of the fact that molecular cohesion is a property 

 of all bodies without any exception whatever. 



This magnificent work divides itself into two 

 stages, which we shall refer to separately : first, 

 the liquefaction of oxygen; and then, following 

 close upon this, the liquefaction of hydrogen, 

 nitrogen, and atmospheric air. 



In the liquefaction of oxygen, which we an- 

 nounced last week as having been accomplished 

 by M: Pictet, of Geneva, we have not only an in- 

 stance of the long time we may have to wait, and 

 of the great difficulties which have to be overcome, 

 before a theoretical conclusion is changed into a 

 concrete fact — something definite acquired to sci- 

 ence ; but also another instance of a double dis- 

 covery, showing that, along all the great lines of 

 thought opened up by modern investigation and 

 modern methods, students of science are march- 

 ing at least two abreast. 



It appears that as early as December 2d 

 M. Cailletet had succeeded in liquefying oxygen 

 and carbonic oxide at a pressure of 300 atmos- 

 pheres and at a temperature of —29° C. This 

 result was not communicated to the Academy 

 at once, but was consigned to a sealed packet 

 on account of M. Cailletet being then a candi- 

 date for a seat in the Section of Mineralogy. 

 Hence, then, the question of priority has been 

 raised, but it is certain that in the future the 

 work will be credited to both, on the ground that 

 the researches of each were absolutely indepen- 

 dent, both pursuing the same object, creating 

 methods and instruments of great complexity. 

 We regret, therefore, that M. Jamin, at the sit- 

 ting of the Academy to which we have referred, 



66 



seemed to strain the claims of M. Cailletet by 

 stating that to obtain the gas non-transparent 

 was the same as to obtain it liquefied. We are 

 beginning to know -enough of the various states 

 of vapor now not to hazard such an assertion as 

 this. This remark, however, rather anticipates 

 matters ; and indeed, as we shall show afterward, 

 M. Cailletet need not himself be very careful of 

 the question of priority — even if it were ever 

 worth caring for except to keep other people 

 honest. 



Owing to the double discovery and the cu- 

 rious incident to which we have referred, the 

 meeting of the Academy on the 24th ult. was a 

 very lively one, as not only was the sealed packet 

 and a subsequent communication from M. Cail- 

 letet read, but M. Pictet had sent a long letter 

 to M. Dumas giving full details of his arrange- 

 ments. MM. Dumas, H. St.-Claire-Deville, Jamin, 

 Regnault, and Berthelot, all took part in the dis- 

 cussion, the former admirably putting the work 

 in its proper place by the following quotation 

 from Lavoisier: 



"... Considerons un moment ce qui arriverait 

 aux differentes substances qui composent le globe, 

 si la temperature en £tait brusquement changee. 

 Supposons, par exemple, que la terre se trouvat 

 transportee tout a coup dans une region heaucoup 

 plus chaude du systeme solaire, dans une region, 

 par exemple, ou la chaleur habituelle serait fort 

 superieure a celle de l'eau bouillante : bientot l'eau, 

 tous les liquides susceptibles de se vaporiser a des 

 degres voisins de l'eau bouillante, et plusieurs sub- 

 stances metalliques meme, entreraient en expan- 

 sion et se transformeraient en fluides aeriformes, 

 qui deviendraient parties de l'atmosphere. 



" Par un effet contraire, si la terre se trouvait 

 tout a coup placee dans des regions tres-froides, 

 par exemple de Jupiter et de Saturne, l'eau qui 

 forme aujourd'hui nos fleuves et nos mers, et pro- 



