1056 Wisconsin Academy of Sciences, Arts s and Letters . 
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Chemical Properties. 
Loss in weight on heating: An examination of the tables 
which follow shows that the oleoresin usually loses between 
20 and 40 per cent, on heating at 100 to 110°C, the variation 
being due to the difference in the volatile oil content. The 
relatively small loss in weight observed in the case of four of 
the laboratory preparations is to be attributed to the removal 
of a part, or the whole, of the more volatile constituents of the 
essential oil in the process of evaporating the solvent. The com¬ 
paratively great loss noted for two of the commercial samples is 
thought to have been due to the presence of unevaporated 
solvent. The results obtained in the determinations made in 
the laboratory as well as those reported in the literature are 
given in the tables which follow: 
Table 53. — Laboratory preparations — loss in weight on heating. 
Sample 
No. 
Date 
Observer 
Solvent 
Per cent of 
loss on drying 
1887 
Kremel .................... 
Alcohol.................... 
At 100° C 
20.40 
1......... 
1916 
DuMez ............ ....... 
Alcohol... 
At 110° C 
23.06 
2,........ 
Acetone ................... 
24.10 
3......... 
Ether ... 
25.88 
4......... 
Petrol, ether .............. 
25.24 
5 __ 
Alcohol ................... 
11.99 
9.96 
8. ........ 
Acetone ................... 
1 ......... 
Ether............. ........ 
8.81 
8..... .... 
Alcohol.................... 
4.71 
Table 54 —Commercial oleoresins—loss in weight on heating. 
Sample 
No. 
Date 
Observer 
Source 
Per cent of 
loss on 
drying 
1......... 
1893 
1894 
1895 
1905 
1916 
Dieterich.................. 
Germany .................. 
At 100 ° C 
32.70 
31.02 
20.90 
55.910) 
At 110° C 
30.72 
31.68 
37.03 
44.21 0) 
61.96 0) 
1 ......... 
1 .... 
1..... ... 
4. 
“ 
1......... 
DuMez ..................... 
Sham & Dohme........... 
2.. 
Stearns & Co.............. 
3......... 
64 
Parke, Davis & Co......... 
4......... 
“ 
Lilly & Co.................. 
6* 
Squibb & Sons............. 
‘Probably contained unevaporated solvent (alcohol). 
