Page:Proceedings of the Royal Society of London Vol 69.djvu/106

98 Contrac-

Contraction

Contraction

Percent-

tion observed

calculated from the

Difference.

calculated from the

Difference.

age.

C x 10- 5.

21 per cent.

33'3 per cent.

origin.

origin.

30-17

f.171

5144

+ 2f5

5227

-56

31-63

5350

5362

-12

5373

-23

32-05

5441

5427

+ 14

5415

+ 26

32 -82

5510

5539

-29

5492

+ 18

33-14

5540

5585

-45

5524

+ 16

33-87

5571

5691

-120

5597

-26

A second example taken from the descending portion, namely, for acids of percentage values from 60*60 to 65*80 per cent., illustrates the same phenomenon.

Contraction

Contraction ]

Pcrcent-

Contrac- tion

calculated from the

Difference.

calculated from the Difference.

observed.

54 per cent.

63'6 per cent.

origin.

origin.

60-60

6592

6584

+ 8

6650 -58

61-53

6528

6517

+ 9

6566 -32

(52 -84

6399

6427

-28

6373 + 26

63-83

6327

6399

-72

6327 nil

65-80

6104

6218

-114

6130 -26

Here also the result for the 60'60 per cent, acid belongs to the straight line drawn from the 53'8 origin, and conversely those for the 63'83 and the 65'8 per cent, acids belong to the straight line drawn from the 6 3 -6 per cent, origin, while the remaining two can equally be represented as belonging to either line.

Secondly, a transition stage, in which the observation points lie upon neither of the straight lines. This is best exemplified by the results obtained at all three temperatures for the alteration at about 20 21 per cent, concentration, which was more particularly investi- gated in consequence of the divergence between the observed and calculated results for the acids of about 19-5 per cent, concentration.

In the three succeeding tables the observed contractions are com- pared with those calculated either forwards or backwards from the two respective origins of co-ordinates.