188 Prof. Williamson on the Unit-volume of Gases. 



Table IV. — Exhibiting by Logarithms (when the unit of Tempe- 

 rature is 10 degrees Centigrade) the law of Increase of the 

 Elastic Force of Steam of Maximum Density, A log A log P 



being equal to — — nearly. 



Absolute 

 tempera- 

 ture 

 (a+t). 



log P. 



A log P. 



log A log P. 



Alog AlogP 

 (--L nearly). 



Absolute 

 tempera- 

 ture 

 (a+t). 



24°-6 

 25-6 

 26-6 

 27-6 

 28-6 

 296 

 30-6 

 316 

 32-6 

 33-6 

 34 6 

 35-6 

 36-6 

 37-6 

 38-6 

 396 

 40-6 

 41-6 

 42-6 

 43-6 

 44-6 

 456 

 46-6 

 47-6 

 48-6 

 49-6 

 50-6 



4-6886930 



3-0831720 

 •4436980 

 •7743170 



1-0784530 

 •3550580 

 •6186550 

 •8594300 



1-0832758 

 •2918492 

 •4866088 

 •6688199 

 •8396183 



o-ooooooo 



•1508529 

 •2929678 

 •4270519 

 ■5537435 

 •6736106 

 •7871694 

 •8948872 

 •9971812 

 i 0944385 

 •1870084 

 •2752035 

 •3593169 

 •4396153 



•3944790 

 •3605260 

 •3306190 

 •3041360 

 •2806050 



2595970 

 •2407750 

 •2238458 

 •2085734 

 •1947596 

 •1822111 

 •1707984 

 •1603817 

 •1508529 

 ■1421149 

 •1340841 

 •1266916 



1198671 

 •1135588 

 •1077178 



1022940 

 •0972573 

 •0925699 

 •0881951 

 •0841134 

 0802984 



1-5960239 

 •5569366 

 •5193278 

 •4830679 

 •4480954 

 •4142997 

 •3816114 

 •3499490 

 •3192588 

 •2894989 

 •2605748 

 •2324837 

 •2051548 

 •1785537 

 152639 

 •1273773 

 1027478 

 •0787001 

 •0552208 

 •0322874 

 •0098502 



2-9879223 

 •9664698 

 •9454445 

 •9248652 

 ■9047069 



•0390873 

 •0376088 

 •0362599 

 0349725 

 •0337957 

 •0326883 

 •0316624 

 0306902 

 •0297599 

 0289241 

 0280911 

 •0273289 

 •0266011 

 0259142 

 •0252622 

 •0246295 

 0240477 

 •0234793 

 •0229334 

 0224372 

 •0219279 

 •0214525 

 0210253 

 0205793 

 0201583 



25-6 

 266 

 27-6 

 28-6 

 29-6 

 30-6 

 31-6 

 32-6 

 33-6 

 346 

 35-6 

 36-6 

 37-6 

 38-6 

 39-6 

 40 6 

 41-6 

 426 

 43-6 

 44-6 

 45-6 

 46-6 

 47-6 

 48-6 

 49-6 



XXVII. On the Unit-volume of Gases. 

 By Professor A. W. Williamson, P.C.S., F.R.S., %c* 



FOR many years the term volume has been employed by che- 

 mists in a specific sense in relation to the weight of gases 

 and vapours. When a chemist speaks of a volume of hydrogen 

 or nitrogen, &c, he is understood to refer to that particular 

 quantity of the gas which is equal in volume to sixteen parts by 

 weight of oxygen. When we say that alcohol, according to the 

 formula C 2 H 6 O, is a two-volume vapour, we thereby say that 

 the weight represented by this formula, namely forty-six parts 



* Communicated by the Author. 



