414 



Dr. H. Herwig on the Expansion 



this small alteration of <£ makes its appearance. The following 

 Table gives the variations of <£ in percentages of the then sub- 

 sisting value of $ for the lowest temperature. The variations 

 are taken from the temperature- and respective pressure-inter- 

 vals, and are calculated for 10° of further heating, In some 



cases, in which somewhat different values of -~ appeared to re- 

 sult for the first part of the observations, the same expression 

 —7- • . ' was calculated separately for this part, and the 



numbers are enclosed in brackets in the Table. But it will be 

 seen that in four instances out of the five this value is smaller 

 than that derived from the entire interval of the observations ; 

 so that the above assertion can decidedly be maintained. If in* 

 isolated places a value of II different by 0*1 millim. were taken 

 (and that, according to what has been said, must be conceived to 

 be the limit of the errors of observation here possible), the course 

 of the values of <p would appear perfectly regular in the given 

 direction. 



Table XX. 



Limits of pressure. 



Limits of 

 temperature. 



100 1OA0 

 (p ' At' 



millim s. 









123- 149 



27-2-88-2 







134- 178 



11-2-89 



+012 



153- 199 



12 6-94-7 







166- 208 



9-3-79-3 







( „ - 192 



„ -53-6 



-0-06) 



197- 240 



16-6-76-5 







203- 246 



17-6-77-7 







250- 303 



16-6-76-5 







369- 423 



36-6-78-6 



+0-07 



( „ -411 



„ -70-3 



+0-04) 



512- 583 



36-6-79-4 



4-015 



741- 817 



51-6-80-7 



+ 0-32 



( „ - 794 



i. -72 



+0-29) 



769- 858 



54-3-90-1 



+0-14 



( „ - 810 



„ -70-4 



+ 0-32) 



1020-1125 



55-8-88-2 



+0-16 



1616-1743 



71-7-961 



+ 0-3 



( „ -1706 



„ -89-5 



+0-18) 



2295-2382 



84-4-973 



+005 



2559-2635 



89 -98 



+0-59 



Before further discussing the results, the observations on the 

 two other vapours may be added. On the first of these, chlo- 

 roform, from the small quantify of my material, I could only 

 execute four series. The numbers are contained in Tables 

 XXI.-XXIV. 



