REGNAULT’S HYGROMETRICAL RESEARCHES, 609 
thod. The weight of the water which filled the bulb was about 
1-5 grm. It was distilled water which had not been boiled; 
consequently it contained the quantity of air which it can dis- 
solve at the ordinary temperature. 
The second column of the table contains the tensions ob- 
served in the air; the third, the elastic forces of the aqueous 
vapour in vacuo, calculated for the same temperatures by means 
of the Table given in page 605. 
Tas Le I.—Tensions of the Vapour of Water in Air, 
_ |Tensions of} Tensions _|Tensions of| Tensions 
— the vapour | calculated | Differ- eer the vapour] calculated 
Centig. Gperyed by the ences, Centig. observed by the 
n air. formula. in air. formula. 
x mm mm mm z mm mm 
0-00 4:47 4:60 —0:13 31:00 32:97 33°41 
12-48 10-08 10°77 —0°69 31-00 33°16 33°41 
12-59 10:31 10°85 —0:°54 34:25 39°98 40°13 
14°57 11-83 12°36 —0°53 18-26 15°06 15°61 
14-60 11-91 12:39 —0-48 18°22 15-04 15°57 
15-00 12-38 12-70 — 0°32 22-12 19-07 19-81 
15°05 12-46 12°74 —0-28 22°15 19-15 19-84 
18°24 15-32 15-59 — 0:27 25°72 24-14 24:59 
18-23 15-48 15°58 —0:10 25°74 24-05 24-62 
21-07 18-28 13-58 —0:30 29-28 29°66 30-25 
21:00 18-27 18-49 —0:22 29-32 29:79 30°35 
23°15 20-74 21-08 —0:34 32°80 36°45 37:00 
23°10 20:77 21-02 —0:25 32°78 36°39 36:96 
24:69 22-70 23:13 —0-43 35:97 43°39 44-13 
24:69 22-73 23:13 —0-40 35°95 43°48 44-08 
27°88 27°59 27:91 | —0-32 37:96 48°70 49-20 
27:96 | —0°31 38-00 48-70 49°30 
Elas' Elastic Elastic Elastic 
force of the force of the ‘ force of the 0=ce of the : 
vapour MADGE Tempera- | vapour vapour Differ- 
Besos ei caleulated . tures. observed in| Calculated ences. 
nitrogen. Pi the Centig- | nitrogen. 
mm A mm 
431 "2 5:27 5-99 
4:43 p , 5:27 5-96 
4:44 : Y 13:12 10°58 
13°29 . , 13°16 10°67 
13°36 ; 62 47-19 14:07 
17:19 14:07 
21:46 18°65 
21:46 18°61 
25°50 23°71 
25°52 23°71 
28°92 28-96 
28°90 28°81 
32°50 35°92 
82°53 36°01 
