NON- VOLATILE CONSTITUENTS OF WINE. 287 



We will now select a few examples of extract ob- 

 tained by direct evaporation and weighing. 



Madeira, freed from water and alcohol, and restored 

 by water alone to its original volume, has a specific 

 weight of from T0169 to T0192 (p. 165). Accord- 

 ing to Balling, we should find in this from 4"25 to 

 4-75 per cent.,* and we find 3'64 4'54 (p. 281) ; 

 Teneriffe, freed from alcohol, has a specific gravity of 

 from 1-0122 to 1'0164 (p. 165). This, according to 

 Balling, must give 3 to 4 per cent, extract ; and we 

 find 2-84 to 3'73 (p. 281). Ehine wine has from 

 1-0083 to 1-0097, specific gravity (p. 166), and should, 

 therefore, contain 2 to 2-5 per cent, extract, and it 

 yields from 1'33 to 2'15 (p. 281). 



The specific gravity of Port wine varies from 1*0167 

 to 1*0227 (p. 166), and should therefore contain from 

 4 to 5'5 per cent, extract, and it gives from 3*75 

 to 5'24 (p. 282). "VVe thus find everywhere lower 

 estimates than those given by Balling, and yet we 

 cannot impugn the experiments. 



A still greater difference becomes apparent if we 

 look more closely into the details of the various 

 estimates. Thus, for example, we find the specific 

 gravity of Madeira freed from alcohol 1-01701-0172 

 -1*0170 (p. 165), and the corresponding extract 

 per cent. 3'83 4-21 3'93 (p. 281). Further, 

 sp. gr. 1-0179 1-0179 1-0179, the three being 

 equal (p. 165), whilst in the extract we find 371 

 3 754-34 (p. 281). 



