; 
368 Researches respecting the Laws of the [May, 
‘itself. It follows in this case, likewise, that the oil has no maximum 
of condensation ; for the equation of this maximum is 
0 = 0'9204416 + 0:002612 T — 0:000011667 T? 
the roots of which are 
T = — 189°, T” = + 413° 
values too remote from our experiments to induce us to consider 
them as applicable. We see that this oil, likewise, congeals without 
dilating. 
Let us examine in the same way the essential oil of thyme. For 
it we have 
D, = 0:949336 T — 0:0001667 T? + 0:0000 T3 
The following table shows the agreement of the formula with 
experiments :— 
¢ 
Mercurial Oil of thyme thermometer. 
Liquid. therm, 
dis Calculated. | Observed. | Difference. 
80 80°00 80:0 0°00 
70 69:07 | 688 | —0-27 
60 58°52 58°3 —0°22 
Essential 50 48°30 48°3 0:00 
oil of 40 38°35 35°4 +0:05 
thyme. 30 28°60 28°6 0:00 
20 19°00 19:0 0:00 
10 9°48 9°4 —0:'08 
0 0:00 0:0 0:00 
Here the agreement is very satisfactory. There is no maximum 
of condensation; for the equation which that maximum would 
give is 
0 = 0:949336 — 0:0003334 T + 0:00003 T? 
the two roots of which are imaginary. Hence that oil will congeal, 
like the last, without dilating. 
We now come to water saturated with common salt. For it we 
have 
D, = 0'820006 T + 00020275 T2 + 0-:000002775 TS 
The comparison of this formula with observation is as follows:— 
