certain nigh-temperature Boiling-points. 

 Table II. — Boiling-points of Sulphur. 



149 



P. 



IV 



T. 



*T. 



P. 



D 20 . 



T. 



*T. 



centim. 



o 



°0. 



°0. 



centim. 



o 



°0. 



°C. 



75-84 



27-976 



446 



448 



6 55 



18-30 



316 



324 



55-36 



26-57 



428 



429 



4-06 



16-80 



295 



305 



55-41 



54-75 



26-59 

 26-49 



429 

 427 



429 



428 











75-87 



27-999 



448 



448 



48-30 



25-87 



420 



422 



30-69 



23-65 



389 



396 



47-78 



25-64 



416 



421 



30-70 



23-65 



389 



396 



37-59 



24-51 



402 



407 



1301 



20-18 



342 



354 



37-57 



24-39 



399 



407 



12-93 



2018 



342 



354 



28-67 



23-44 



386 



393 



5-61 



17-28 



302 



317 



28-80 



23-51 



387 



394 



5-91 



17'51 



305 



320 



20-68 



22-23 



370 



376 



6-14 



17-62 



306 



321 



20-70 



22-25 



370 



376 



3-29 



15-55 



278 



295 



14-37 



20-76 



349 



358 



3-44 



15-51 



277 



297 



14-49 



20-73 



348 



359 



1-67 



11-21 



228 



275 



1115 



19-66 



335 



346 



1-39 



11-85 



1223 



266 



11-25 



19-77 



336 



347 



105 



11-33 



t215 



260 



6-11 



18-05 



313 



321 



0-75 



10-76 



1206 



252 



6-35 



18-20 



315 



323 











* Extrapolated by Eegnault-Bertrand's formula. 



t Sulphur sticky. 



These results agree fairly well with those of the earlier 

 Table. I have added values of T extrapolated graphically § 

 from Regnault's data by aid of the Dupre-Bertrand equation 

 (§ 12) log p = 19-10740 - 4684-49/0 - 3-40483 log (9, which 

 holds between 6 = 663 and = 843 absolute degrees Centi- 

 grade. It will be seen by comparison of my values with the 

 data predicted by this formula that there is much error at low 

 pressures. 



8. Table III. contains data of four sets of experiments with 

 zinc. The first of these were made in the glass tube (fig. 1) 

 at low pressure. Although in this case there was profuse 

 volatilization, I did not observe any ebullition. In the table 

 the result marked * is the only datum of this work inserted. 

 Change of temperature with pressure was not obvious. The 

 remaining data of this part of the table are legitimate and 

 were obtained from crucible experiments (fig. 2). The 

 criterion of boiling-point is change of temperature with 

 pressure. In the second and third parts of the Table, I aimed 

 at greater accuracy. Each of the values given is a mean of 

 two or three distinct measurements, f refers to low position. 

 and J to a high position of the thermocouple in the central 

 tube be b, figure 2. 



§ I computed the inferior prolongation of the curve, and plotted the 

 results. From the chart the values of T were taken correct to 1 degree. 



