PHYSICAL CHARACTERS OF MIXTURES OF ALCOHOL AND WATER. 
609 
It was found that the temperature of the specific-gravity bottle could be kept within 
about p of a degree of the temperature of the water-bath ; a more exact coincidence 
is not required, as the possible error thus made is quite within the unavoidable errors in 
filling, weighing, &c. 
The bottle was weighed on a balance which turned readily with 0-0005 grm., the 
empty bottle being counterpoised by a second bottle of the same size and shape, to avoid 
any errors from hygrometric moisture. 
The thermometer and barometer were observed every time a weighing was made, and 
the true weight in vacuo calculated in each case. 
The mixtures were made by gradually diluting the stronger mixtures, from nearly 
absolute alcohol downwards; and after being made, the mixtures were exposed for 
twenty-four hours in the exhausted receiver of an air-pump, so that any air present 
might be removed. 
Owing to a slight mistake in making some of the mixtures, they are not of the exact 
strength desired. 
Weight of distilled water in specific-gravity bottle 
at 10°-0 C. 545-3507 grms., 
15°-5 C. 545-0540 grms., 
20 o, 0 C. 544-6705 grms. 
The volume of the bottle will therefore be, adopting Matthiessen’s results for the 
expansion of water, 
at 10°*0 C. 545-4985 cub. centims., 
15°-5 C. 545*5843 cub. centims., 
20 o, 0 C. 545-6585 cub. centims. 
Table XI. 
Per cent, of alcohol, 
by weight. 
Specific gravity at 
Specific gravity at 
15°-5 C. 
Specific gravity at 
20° C. 
10 
98396 
98298 
98189 
20 
97261 
97054 
96866 
30 
95995 
95666 
95392 
40 
94253 
93854 
93520 
45 
93262 
92846 
92496 
50 
92185 
91745 
91390 
59*77 
89994 
89545 
89179 
69-70 
87695 
87219 
86844 
79-81 
85271 
84797 
84410 
89-89 
82712 
82240 
81851 
100-00 
79792 
79317 
78932 
