38 



Drs. Ramsay and Young on 



The determination of the vapour-pressures of a large series of 

 compound ethers by Schumann (Wiedemann's Annalen, 1881, 

 p. 40) affords an opportunity of studying the relations of a great 

 number of bodies of the same type ; and it appears that in this 

 case also the ratio of the absolute temperatures of any two of 

 the ethers is a constant at all pressures. The following table 

 shows the ratios of the absolute temperatures of all the ethers 

 to those of ethyl acetate at pressures of 200, 760, and 1300 

 millims. (The boiling-points at these pressures are given by 

 Schumann.) It will be seen that in every case the ratio is 

 very nearly constant at each pressure ; and the deviations 

 from constancy may well be due to the great difficulty of ob- 

 taining perfectly pure specimens, evidenced by the fact that 

 only one ether boiled with perfect constancy, the rise of tem- 

 perature during distillation amounting in one case to o, 7, 

 while the average rise was o, 37. The absolute temperatures 

 of ethyl acetate corresponding to 1300, 760, and 200 millim. 

 are 367°-3, 350°-l, and 314°-4. 



Ratios of Absolute Temperatures of Ethers to those of Ethyl 

 Acetate at definite Pressures. 



Ether. 



Pressure. 



Mean. 



1300 

 millim. 



760 

 millim. 



200 

 millim. 



Methyl formate 



•8715 

 •9344 

 1-0109 

 1-0585 

 1-1345 

 •9420 

 1-0678 

 1-1122 

 1-0073 

 1-0615 

 1-1290 

 11704 

 1-2366 

 1-0724 

 1-1220 

 1-1889 

 1-2279 

 1-2905 

 1-0444 

 1-0953 

 11604 

 1-2001 

 1-2644 

 1-1135 

 11642 

 1-2257 

 1-2635 



•8720 

 •9352 

 1-0111 

 1-0594 

 1-1320 

 •9440 

 1-0677 

 1-1120 

 1-0080 

 1-0605 

 1-1288 

 11705 

 1-2374 

 1-0720 

 1-1223 

 1-1874 

 1-2279 

 1-2899 

 1-0434 

 1-0943 

 1-1623 

 1-1985 

 1-2619 

 1-1131 

 1-1634 

 1-2251 

 1-2617 



•8706 

 •9323 

 10115 

 1-0573 

 1-1329 

 •9431 

 1-0690 

 1-1120 

 1-0073 

 1-0614 

 1-1291 

 11705 

 1-2401 

 1-0716 

 1-1202 

 1-1902 

 1-2278 

 1-2901 

 10433 

 1-0935 

 1-1609 

 1-1985 

 1-2637 

 1-1139 

 1-1619 

 1-2265 

 1-2634 



•8714 

 •9340 

 10112 

 1-0584 

 11331 

 1-9430 

 1-0682 

 1-1121 

 1-0075 

 1-0611 

 1-1290 

 1-1705 

 1-2380 

 1-0720 

 11215 

 11888 

 1-2279 

 1-2902 

 1-0437 

 1-0944 

 11612 

 1-1990 

 1-2633 

 1-1135 

 1-1632 

 1-2258 

 1-2629 



Ethyl formate 



Propyl formate 



Isobutyl formate 



Amyl formate 



Methyl acetate 



Propyl acetate 



Isobutyl acetate 



Methyl propionate 



Ethyl propionate 



Propyl propionate ... 



Isobutyl propionate 



Amyl propionate 



Methyl butyrate 



Ethyl butyrate 



Propyl butyrate 



Isobutyl butyrate 



Amyl butyrate 



Methyl isobutyrate 



Ethyl isobutyrate 



Propyl isobutyrate . . 



Isobutyl isobutyrate 



Amyl isobutyrate 



Methyl valerate 



Ethyl valerate 









