Principles and practice of agricultural analysis. Volume 3 (of 3), Agricultural products

by Harvey Washington Wiley

Correction Table for Specific Gravity.

Below 15°.6 Subtract; Above 15°.6 Add.

Temp.	Correction.	Temp.	Correction.	Temp.	Correction.
12.2	0.00047	18.2	0.00043	24.2	0.00163
12.4	0.00044	18.4	0.00046	24.4	0.00167
12.6	0.00042	18.6	0.00050	24.6	0.00172
12.8	0.00039	18.8	0.00053	24.8	0.00176
13.0	0.00037	19.0	0.00057	25.0	0.00181
13.2	0.00634	19.2	0.00061	25.2	0.00186
13.4	0.00032	19.4	0.00065	25.4	0.00191
13.6	0.00029	19.6	0.00068	25.6	0.00195
13.8	0.00027	19.8	0.00072	25.8	0.00200
14.0	0.00024	20.0	0.00076	26.0	0.00205
14.2	0.00021	20.2	0.00080	26.2	0.00210
14.4	0.00018	20.4	0.00084	26.4	0.00215
14.6	0.00015	20.6	0.00087	26.6	0.00220
14.8	0.00012	20.8	0.00091	26.8	0.00225
15.0	0.00009	21.0	0.00095	27.0	0.00230
15.2	0.00006	21.2	0.00099	27.2	0.00235
15.4	0.00003	21.4	0.00103	27.4	0.00240
15.6	0.00000	21.6	0.00107	27.6	0.00246
15.8	0.00003	21.8	0.00111	27.8	0.00251
16.0	0.00006	22.0	0.00115	28.0	0.00256
16.2	0.00009	22.2	0.00119	28.2	0.00261
16.4	0.00012	22.4	0.00123	28.4	0.00267
16.6	0.00016	22.6	0.00128	28.6	0.00272
16.8	0.00019	22.8	0.00132	28.8	0.00278
17.0	0.00022	23.0	0.00136	29.0	0.00283
17.2	0.00025	23.2	0.00140	29.2	0.00288
17.4	0.00029	23.4	0.00145	29.4	0.00294
17.6	0.00032	23.6	0.00149	29.6	0.00299
17.8	0.00036	23.8	0.00154	29.8	0.00306
18.0	0.00039	24.0	0.00158	30.0	0.00311

The table is only accurate when the distillate does not contain over seven nor less than three per cent of alcohol. If the distillate contain more than seven per cent of alcohol it is diluted and the compensating correction made.

620. Calculating Results.—The specific gravity of the alcoholic distillate having been determined by any approved method and corrected to a temperature of 15°.6, the corresponding per cents of alcohol by volume and by weight are found by consulting the following table.[636] If, for example, the corrected specific gravity be exactly that given in any figure of the table the corresponding per cents are directly read. If the specific gravity found fall between two numbers in the table the corresponding per cents are determined by interpolation.

Table Showing Percentage of Alcohol
by Weight and by Volume.

Specific gravity at 15°.6./15°.6.	Per cent alcohol by volume.	Per cent alcohol by weight.
1.00000	0.00	0.00
0.99992	.05	.04
984	.10	.08
976	.15	.12
968	.20	.16
961	.25	.20
953	.30	.24
945	.35	.28
937	.40	.32
930	.45	.36
.99923	0.50	0.40
915	.55	.44
907	.60	.48
900	.65	.52
892	.70	.56
884	.75	.60
877	.80	.64
869	.85	.67
861	.90	.71
854	.95	.75
.99849	1.00	0.79
842	.05	.83
834	.10	.87
827	.15	.91
819	.20	.95
812	.25	.99
805	.30	1.03
797	.35	.07
790	.40	.11
782	.45	.15
.99775	1.50	1.19
768	.55	.23
760	.60	.27
753	.65	.31
745	.70	.35
738	.75	.39
731	.80	.43
723	.85	.47
716	.90	.51
708	.95	.55
.99701	2.00	1.59
694	.05	.63
687	.10	.67
679	.15	.71
672	.20	.75
665	.25	.79
658	.30	.83
651	.35	.87
643	.40	.91
636	.45	.95
0.99629	2.50	1.99
622	.55	2.03
615	.60	.07
607	.65	.11
600	.70	.15
593	.75	.19
586	.80	.23
579	.85	.27
571	.90	.31
564	.95	.35
.99557	3.00	2.39
550	.05	.43
543	.10	.47
536	.15	.51
529	.20	.55
522	.25	.59
515	.30	.64
508	.35	.68
501	.40	.72
494	.45	.76
.99487	3.50	2.80
480	.55	.84
473	.60	.88
466	.65	.92
459	.70	.96
452	.75	3.00
445	.80	.04
438	.85	.08
431	.90	.12
424	.95	.16
.99417	4.00	3.20
410	.05	.24
403	.10	.28
397	.15	.32
390	.20	.36
383	.25	.40
376	.30	.44
369	.35	.48
363	.40	.52
356	.45	.56
.99349	4.50	3.60
342	.55	.64
335	.60	.68
329	.65	.72
322	.70	.76
315	.75	.80
308	.80	.84
301	.85	.88
295	.90	.92
288	.95	.96
0.99281	5.00	4.00
274	.05	.04
268	.10	.08
261	.15	.12
255	.20	.16
248	.25	.20
241	.30	.24
235	.35	.28
228	.40	.32
222	.45	.36
.99215	5.50	4.40
208	.55	.44
202	.60	.48
195	.65	.52
189	.70	.56
182	.75	.60
175	.80	.64
169	.85	.68
162	.90	.72
156	.95	.76
.99149	6.00	4.80
143	.05	.84
136	.10	.87
130	.15	.92
123	.20	.96
117	.25	5.00
111	.30	.05
104	.35	.09
098	.40	.13
091	.45	.17
.99085	6.50	5.21
079	.55	.25
072	.60	.29
066	.65	.33
059	.70	.37
053	.75	.41
047	.80	.45
040	.85	.49
034	.90	.53
027	.95	.57
.99021	7.00	5.61
015	.05	.65
009	.10	.69
002	.15	.73
.98996	.20	.77
990	.25	.81
984	.30	.86
978	.35	.90
971	.40	.94
965	.45	.98
0.98959	7.50	6.02
953	.55	.06
947	.60	.10
940	.65	.14
934	.70	.18
928	.75	.22
922	.80	.26
916	.85	.30
909	.90	.34
903	.95	.38
.98897	8.00	6.42
891	.05	.46
885	.10	.50
879	.15	.54
873	.20	.58
867	.25	.62
861	.30	.67
855	.35	.71
849	.40	.75
843	.45	.79
.98837	8.50	6.83
831	.55	.87
825	.60	.91
819	.65	.95
813	.70	.99
807	.75	7.03
801	.80	.07
795	.85	.11
789	.90	.15
783	.95	.19
.98777	9.00	7.23
771	.05	.27
765	.10	.31
754	.20	.39
748	.25	.43
742	.30	.48
736	.35	.52
724	.45	.60
.98719	9.50	7.64
713	.55	.68
707	.60	.72
701	.65	.76
695	.70	.80
689	.75	.84
683	.80	.88
678	.85	.92
672	.90	.96
666	.95	8.00
0.98660	10.00	8.04
654	.05	.08
649	.10	.12
643	.15	.16
637	.20	.20
632	.25	.24
626	.30	.28
620	.35	.33
614	.40	.37
609	.45	.41
.98603	10.50	8.45
597	.55	.49
592	.60	.53
586	.65	.57
580	.70	.61
575	.75	.65
569	.80	.70
563	.85	.74
557	.90	.78
552	.95	.82
.98546	11.00	8.86
540	.05	.90
535	.10	.94
529	.15	.98
524	.20	9.02
518	.25	.07
513	.30	.11
507	.35	.15
502	.40	.19
496	.45	.23
.98491	11.50	9.27
485	.55	.31
479	.60	.35
474	.65	.39
468	.70	.43
463	.75	.47
457	.80	.51
452	.85	.55
446	.90	.59
441	.95	.63
.98435	12.00	9.67
430	.05	.71
424	.10	.75
419	.15	.79
413	.20	.83
408	.25	.87
402	.30	.92
397	.35	.96
391	.40	10.00
386	.45	.04
0.98381	12.50	10.08
375	.55	.12
370	.60	.16
364	.65	.20
359	.70	.24
353	.75	.28
348	.80	.33
342	.85	.37
337	.90	.41
331	.95	.45
.98326	13.00	10.49
321	.05	.53
315	.10	.57
310	.15	.61
305	.20	.65
299	.25	.69
294	.30	.74
289	.35	.78
283	.40	.82
278	.45	.86
.98273	13.50	10.90
267	.55	.94
262	.60	.98
256	.65	11.02
251	.70	.06
246	.75	.14
240	.80	.15
235	.85	.19
230	.90	.23
224	.95	.27
.98219	14.00	11.31
214	.05	.35
209	.10	.39
203	.15	.43
198	.20	.47
193	.25	.52
188	.30	.56
182	.35	.60
177	.40	.64
172	.45	.68
.98167	14.50	11.72
161	.55	.76
156	.60	.80
151	.65	.84
146	.70	.88
140	.75	.93
135	.80	.97
130	.85	12.01
125	.90	.05
119	.95	.09
0.98114	15.00	12.13
108	.05	.17
104	.10	.21
099	.15	.25
093	.20	.29
088	.25	.33
083	.30	.38
078	.35	.42
073	.40	.46
068	.45	.50
.98063	15.50	12.54
057	.55	.58
052	.60	.62
047	.65	.66
042	.70	.70
037	.75	.75
032	.80	.79
026	.85	.83
021	.90	.87
016	.95	.91
.98011	16.00	12.95
005	.05	.99
001	.10	13.03
.97996	.15	.08
991	.20	.12
986	.25	.16
980	.30	.20
975	.35	.24
970	.40	.29
965	.45	.33
.97960	16.50	13.37
955	.55	.41
950	.60	.45
945	.65	.49
940	.70	.53
935	.75	.57
929	.80	.62
924	.85	.66
919	.90	.70
914	.95	.74
.97909	17.00	13.78
904	.05	.82
899	.10	.86
894	.15	.90
889	.20	.94
884	.25	.98
879	.30	14.03
874	.35	.07
869	.40	.11
864	.45	.15
0.97859	17.50	14.19
853	.55	.23
848	.60	.27
843	.65	.31
838	.70	.35
833	.75	.40
828	.80	.44
823	.85	.48
818	.90	.52
813	.95	.56
.97808	18.00	14.60
803	.05	.64
798	.10	.68
793	.15	.73
788	.20	.77
783	.25	.81
778	.30	.85
773	.35	.89
768	.40	.94
763	.45	.98
.97758	18.50	15.02
753	.55	.06
748	.60	.10
743	.65	.14
738	.70	.18
733	.75	.22
728	.80	.27
723	.85	.31
718	.90	.35
713	.95	.39
.97708	19.00	15.43
703	.05	.47
698	.10	.51
693	.15	.55
688	.20	.59
683	.25	.63
678	.30	.68
673	.35	.72
668	.40	.76
663	.45	.80
.97658	19.50	15.84
653	.55	.88
648	.60	.93
643	.65	.97
638	.70	16.01
633	.75	.05
628	.80	.09
623	.85	.14
618	.90	.18
613	.95	.22
0.97608	20.00	16.26
603	.05	.30
598	.10	.34
593	.15	.38
588	.20	.42
583	.25	.46
578	.30	.51
573	.35	.58
568	.40	.59
563	.45	.63
.97558	20.50	16.67
552	.55	.71
547	.60	.75
542	.65	.80
537	.70	.84
532	.75	.88
527	.80	.92
522	.85	.96
517	.90	17.01
512	.95	.05
.97507	21.00	17.09
502	.05	.13
497	.10	.17
492	.15	.22
487	.20	.26
482	.25	.30
477	.30	.34
472	.35	.38
467	.40	.43
462	.45	.47
.97457	21.50	17.51
451	.55	.55
446	.60	.59
441	.65	.63
436	.70	.67
431	.75	.71
426	.80	.76
421	.85	.80
416	.90	.84
411	.95	.88
.97406	22.00	17.92
401	.05	.96
396	.10	18.00
391	.15	.05
386	.20	.09
381	.25	.13
375	.30	.17
370	.35	.21
365	.40	.26
360	.45	.30
0.97355	22.50	18.34
350	.55	.38
345	.60	.42
340	.65	.47
335	.70	.51
330	.75	.55
324	.80	.59
319	.85	.63
314	.90	.68
309	.95	.72
.97304	23.00	18.76
299	.05	.80
294	.10	.84
289	.15	.88
283	.20	.92
278	.25	.96
273	.30	19.01
268	.35	.05
263	.40	.09
258	.45	.13
.97253	23.50	19.17
247	.55	.21
242	.60	.25
237	.65	.30
232	.70	.34
227	.75	.38
222	.80	.42
216	.85	.46
211	.90	.51
206	.95	.55
.97201	24.00	19.59
196	.05	.63
191	.10	.67
185	.15	.72
180	.20	.76
175	.25	.80
170	.30	.84
165	.35	.88
159	.40	.93
154	.45	.97
.97149	24.50	20.01
144	.55	.05
139	.60	.09
133	.65	.14
128	.70	.18
123	.75	.22
118	.80	.26
113	.85	.30
107	.90	.35
102	.95	.39
0.97097	25.00	20.43
092	.05	.47
086	.10	.51
081	.15	.56
076	.20	.60
071	.25	.64
065	.30	.68
060	.35	.72
055	.40	.77
049	.45	.81
.97014	25.50	20.85
039	.55	.89
033	.60	.93
028	.65	.98
023	.70	21.02
018	.75	.06
012	.80	.10
007	.85	.14
001	.90	.19
.96996	.95	.23
.96991	26.00	21.27
986	.05	.31
980	.10	.35
975	.15	.40
969	.20	.44
964	.25	.48
959	.30	.52
953	.35	.56
949	.40	.61
942	.45	.65
.96937	26.50	21.69
932	.55	.73
926	.60	.77
921	.65	.82
915	.70	.86
910	.75	.90
905	.80	.94
899	.85	.98
894	.90	22.03
888	.95	.07
.96883	27.00	22.11
877	.05	.15
872	.10	.20
866	.15	.24
861	.20	.28
855	.25	.33
850	.30	.37
844	.35	.41
839	.40	.45
833	.45	.50
0.96828	27.50	22.54
822	.55	.58
816	.60	.62
811	.65	.67
805	.70	.71
800	.75	.75
794	.80	.79
789	.85	.83
783	.90	.88
778	.95	.92
.96772	28.00	22.96
766	.05	23.00
761	.10	.04
755	.15	.09
749	.20	.13
744	.25	.17
738	.30	.21
732	.35	.25
726	.40	.30
721	.45	.34
.96715	28.50	23.38
709	.55	.42
704	.60	.47
698	.65	.51
692	.70	.55
687	.75	.60
681	.80	.64
675	.85	.68
669	.90	.72
664	.95	.77
.96658	29.00	23.81
652	.05	.85
646	.10	.89
640	.15	.94
635	.20	.98
629	.25	24.02
623	.30	.06
617	.35	.10
611	.40	.15
605	.45	.19
.96600	29.50	24.23
594	.55	.27
587	.60	.32
582	.65	.36
576	.70	.40
570	.75	.45
564	.80	.49
559	.85	.53
553	.90	.57
547	.95	.62
0.96541	30.00	24.66
535	.05	.70
529	.10	.74
523	.15	.79
517	.20	.83
511	.25	.87
505	.30	.91
499	.35	.95
493	.40	25.00
487	.45	.04
.96481	30.50	25.08
475	.55	.12
469	.60	.17
463	.65	.21
457	.70	.25
451	.75	.30
445	.80	.34
439	.85	.38
433	.90	.42
427	.95	.47
.96421	31.00	25.51
415	.05	.55
409	.10	.60
403	.15	.64
396	.20	.68
390	.25	.73
384	.30	.77
378	.35	.81
372	.40	.85
366	.45	.90
.96360	31.50	25.94
353	.55	.98
347	.60	26.03
341	.65	.07
335	.70	.11
329	.75	.16
323	.80	.20
316	.85	.24
310	.90	.28
304	.95	.33
.96298	32.00	26.37
292	.05	.41
285	.10	.46
279	.15	.50
273	.20	.54
267	.25	.59
260	.30	.63
254	.35	.67
248	.40	.71
241	.45	.76
0.96235	32.50	26.80
229	.55	.84
222	.60	.89
216	.65	.93
210	.70	.97
204	.75	27.02
197	.80	.06
191	.85	.10
185	.90	.14
178	.95	.19
.96172	33.00	27.23
166	.05	.27
159	.10	.32
153	.15	.36
146	.20	.40
140	.25	.45
133	.30	.49
127	.35	.53
120	.40	.57
114	.45	.62
.96108	33.50	27.66
101	.55	.70
095	.60	.75
088	.65	.79
082	.70	.83
075	.75	.88
069	.80	.92
062	.85	.97
056	.90	28.00
049	.95	.05
.96043	34.00	28.09
036	.05	.13
030	.10	.18
023	.15	.22
016	.20	.26
010	.25	.31
003	.30	.35
.95996	.35	.39
990	.40	.43
983	.45	.48
.95977	34.50	28.52
970	.55	.56
963	.60	.61
957	.65	.65
950	.70	.70
943	.75	.74
937	.80	.78
930	.85	.83
923	.90	.87
917	.95	.92
0.95910	35.00	28.96
903	.05	29.00
896	.10	.05
889	.15	.09
883	.20	.13
876	.25	.18
869	.30	.22
862	.35	.26
855	.40	.30
848	.45	.35
.95842	35.50	29.39
835	.55	.43
828	.60	.48
821	.65	.52
814	.70	.57
807	.75	.61
800	.80	.65
794	.85	.70
787	.90	.74
780	.95	.79
.95773	36.00	29.83
766	.05	.87
759	.10	.92
752	.15	.96
745	.20	30.00
738	.25	.05
731	.30	.09
724	.35	.13
717	.40	.17
710	.45	.22
.95703	36.50	30.26
695	.55	.30
688	.60	.35
681	.65	.39
674	.70	.44
667	.75	.48
660	.80	.52
653	.85	.57
646	.90	.61
639	.95	.66
.95632	37.00	30.70
625	.05	.74
618	.10	.79
610	.15	.83
603	.20	.88
596	.25	.92
589	.30	.96
581	.35	31.01
574	.40	.05
567	.45	.10
0.95560	37.50	31.14
552	.55	.18
545	.60	.23
538	.65	.27
531	.70	.32
523	.75	.36
516	.80	.40
509	.85	.45
502	.90	.49
494	.95	.54
.95487	38.00	31.58
480	.05	.63
472	.10	.67
465	.15	.72
457	.20	.76
450	.25	.81
442	.30	.85
435	.35	.90
427	.40	.94
420	.45	.99
.95413	38.50	32.03
405	.55	.07
398	.60	.12
390	.65	.16
383	.70	.20
375	.75	.25
368	.80	.29
360	.85	.33
353	.90	.37
345	.95	.42
.95338	39.00	32.46
330	.05	.50
323	.10	.55
315	.15	.59
307	.20	.64
300	.25	.68
292	.30	.72
284	.35	.77
277	.40	.81
269	.45	.86
.95262	39.50	32.90
254	.55	.95
246	.60	.99
239	.65	33.04
231	.70	.08
223	.75	.13
216	.80	.17
208	.85	.22
200	.90	.27
193	.95	.31
0.95185	40.00	33.35
177	.05	.39
169	.10	.44
161	.15	.48
154	.20	.53
146	.25	.57
138	.30	.61
130	.35	.66
122	.40	.70
114	.45	.75
.95107	40.50	33.79
099	.55	.84
091	.60	.88
083	.65	.93
075	.70	.97
067	.75	34.02
059	.80	.06
052	.85	.11
044	.90	.15
036	.95	.20
.95028	41.00	34.24
020	.05	.28
012	.10	.33
004	.15	.37
.94996	.20	.42
988	.25	.46
980	.30	.50
972	.35	.55
964	.40	.59
956	.45	.64
.94948	41.50	34.68
940	.55	.73
932	.60	.77
924	.65	.82
916	.70	.86
908	.75	.91
900	.80	.95
892	.85	35.00
884	.90	.04
876	.95	.09
.94868	42.00	35.13
860	.05	.18
852	.10	.22
843	.15	.27
835	.20	.31
827	.25	.36
820	.30	.40
811	.35	.45
802	.40	.49
794	.45	.54
0.94786	42.50	35.58
778	.55	.63
770	.60	.67
761	.65	.72
753	.70	.76
745	.75	.81
737	.80	.85
729	.85	.90
720	.90	.94
712	.95	.99
.94704	43.00	36.03
696	.05	.08
687	.10	.12
679	.15	.17
670	.20	.21
662	.25	.23
654	.30	.30
645	.35	.35
637	.40	.39
628	.45	.44
.94620	43.50	36.48
612	.55	.53
603	.60	.57
595	.65	.62
586	.70	.66
578	.75	.71
570	.80	.75
561	.85	.80
553	.90	.84
544	.95	.89
.94536	44.00	36.93
527	.05	.98
519	.10	37.02
510	.15	.07
502	.20	.11
493	.25	.16
484	.30	.21
476	.35	.25
467	.40	.30
459	.45	.34
.94450	44.50	37.39
441	.55	.44
433	.60	.48
424	.65	.53
416	.70	.57
407	.75	.62
398	.80	.66
390	.85	.71
381	.90	.76
373	.95	.80
0.94364	45.00	37.84
355	.05	.89
346	.10	.93
338	.15	.98
329	.20	38.02
320	.25	.07
311	.30	.12
302	.35	.16
294	.40	.21
285	.45	.25
.94276	45.50	38.30
267	.55	.35
258	.60	.39
250	.65	.44
241	.70	.48
232	.75	.53
223	.80	.57
214	.85	.62
206	.90	.66
197	.95	.71
.94188	46.00	38.75
179	.05	.80
170	.10	.84
161	.15	.89
152	.20	.93
143	.25	.98
134	.30	39.03
125	.35	.07
116	.40	.12
107	.45	.16
.94098	46.50	39.21
089	.55	.26
080	.60	.30
071	.65	.35
062	.70	.39
053	.75	.44
044	.80	.49
035	.85	.53
026	.90	.58
017	.95	.62
.94008	47.00	39.67
.93999	.05	.72
990	.10	.76
980	.15	.81
971	.20	.85
962	.25	.90
953	.30	.95
944	.35	.99
934	.40	40.04
925	.45	.08
0.93916	47.50	40.13
906	.55	.18
898	.60	.22
888	.65	.27
879	.70	.32
870	.75	.37
861	.80	.41
852	.85	.46
842	.90	.51
833	.95	.55
.93824	48.00	40.60
815	.05	.65
808	.10	.69
796	.15	.74
786	.20	.78
777	.25	.83
768	.30	.88
758	.35	.92
740	.40	.97
739	.45	41.01
.93730	48.50	41.06
721	.55	.11
711	.60	.15
702	.65	.20
692	.70	.24
683	.75	.29
673	.80	.34
664	.85	.38
655	.90	.43
645	.95	.47
.93636	49.00	41.52
626	.05	.57
617	.10	.61
607	.15	.66
598	.20	.71
588	.25	.76
578	.30	.80
569	.35	.85
559	.40	.90
550	.45	.94
.93540	49.50	41.99
530	.55	42.04
521	.60	.08
511	.65	.13
502	.70	.18
492	.75	.23
482	.80	.27
473	.85	.32
463	.90	.37
454	.95	.41

621. Determination of Percentage of Alcohol by Means Of Vapor Temperature.—The temperature of a mixture of alcohol and water vapors is less than that of water alone and the depression is inversely proportional to the quantity of alcohol present. This principle is utilized in the construction of the ebullioscope or ebulliometer. In this apparatus the temperature of pure boiling water vapor is determined by a preliminary experiment. This point must be frequently revised in order to correct it for variations in barometric pressure. The water is withdrawn from the boiler of the apparatus, the same volume of a wine or beer placed therein, and the vapor temperature again determined. By comparing the boiling point of the wine, with a scale calibrated for different percentages of alcohol, the quantity of spirit present is determined. When water vapor is at 100° a vin ordinaire having eight per cent of alcohol gives a vapor at 93°.8. The presence of extractive matters in the sample, which tend to raise its boiling point, is neglected in the calculation of results.

622. Improved Ebullioscope.—The principle mentioned in the above paragraph may be applied with a considerable degree of accuracy, by using the improved ebullioscope described below.[637]

The apparatus consists of a glass flask F, shaped somewhat like an erlenmeyer, closed at the top with a rubber stopper carrying a central aperture for the insertion of the delicate thermometer A B, and a lateral smaller aperture for connecting the interior of the flask with the condenser D. The return of the condensed vapors from D is effected through the tube entering the flask F in such a manner as to deliver the condensed liquid beneath the surface of the liquid in F as shown in the [figure]. The flask F contains pieces of scrap platinum or pumice stone to prevent bumping and secure an even ebullition. The flask F rests upon a disk of asbestos, perforated in such a way as to have the opening fully covered by the bottom of the flask. To protect F against the influence of air currents it is enclosed in the glass cylinder E resting on the asbestos disk below and closed with a detachable soft rubber cover at the top. The temperature between the cylinder E and the flask F is measured by the thermometer C and the flame of the lamp G should be so adjusted as to bring the temperature between the flask F and the cylinder E to about 90° at the time of reading the thermometer B. The bulb of the thermometer B may be protected by a thin glass tube carrying distilled water, so adjusted as to prevent the escape of the watery vapor into F. The thermometer B is such as is used for determining molecular weights by the cryoscopic method. It has a cistern at A which holds any excess of mercury not needed in adjusting the thermometer for any required temperature.