100 Progress of Foreign Science. 



Remarks on the Results contained in the above Tables. 



In the first experiment, the ether passed into the state of va- 

 pour at 150°, and produced a pressure of 37 atmospheres. 



The sulphuret of carbon, which is almost as volatile as ether, 

 passed however into the state of vapour only at 220°, with a pres- 

 sure of about 78 atmospheres, that is to say, double of the ether. 

 This result is the more remarkable since the capacity of the tube 

 which enclosed this liquid, was a little larger, in reference to the 

 volume, than for the ether. 



The irregularities observed in the succession of the noted pres- 

 sures, depend probably on some inaccuracies which may have 

 slipped into the experiments, notwithstanding every precaution. 

 They have, however, no sensible influence on the main results. 

 From the table of the first experiments on ether, we perceive that 

 from 140° to 160°, the pressure increased by an atmosphere for 

 each degree; that however, at a much higher temperature, namely, 

 from 240° to 260°, the increase of pressure was only half an at- 

 mosphere for a degree ; and that finally, at 260° the pressure be- 

 came again stronger, a circumstance proceeding probably from the 

 decomposition of the ether, or from some analogous change oi'state. 



It appears from the experiments made on the sulphuret of car- 

 bon, that from 250° to 260°, the augmentation of pressure was an 

 atmosphere and a half for each degree, and that at 266°, this in- 

 crease lessened as with ether. 



On comparing together the two tables concerning ether, we ob- 

 serve that up to 150°, the pressures in the tube with least liquid, are 

 stronger than those of the other tube which contained the double. 

 This difference arises undoubtedly from the primitive attraction of 

 liquidity preserving, at these temperatures, least influence in the tube 

 where the particles of the vapour are more diffused than in the other. 



We may remark, in these tables, especially in the second of the 

 experiments on ether, that it is in general when the liquid is in the 

 state of vapour, that the increase of the pressures is the greatest. 

 It soon diminishes, and seems thereafter to follow the same rate as 

 in gases. From the same two tables, we further perceive that the 

 total vaporization of the liquid, in the two experiments, occurred 

 at temperatures slightly different. This circumstance would seem 

 to demonstrate thrt this peculiar state always requires a very ele- 

 vated temperature, nearly independent of the capacity of the tube. 

 Ann. de Chim. etde Phys., xxii. 140. 



3- On the Sulphurets resulting from the reduction of some Sulphates, 

 by means of Charcoal. By M. P. Berthier. 



This diligent chemist confirms in this paper, the views of Berze- 

 lius, of which we formerly gave an account *, concerning the con- 

 stitution of the sulphurets ; namely, that they are compounds of the 



* Vol. xv. p. 209. 



