THE GRAPE. 33 



THE ALBUMINOUS SUBSTANCES. 



We are acquainted with but few good analyses of 

 the albuminous bodies found in grapes. Sometimes 

 albumen, sometimes gluten, and sometimes both are 

 spoken of. Beltz is the only person who has ven- 

 tured to determine the quantities of these ingredients, 

 and how he ascertained them remains a question. 

 Beltz- analysed the must of the Eiessling grapes of 

 Grumbach, and found in a quart, the specific gravity 

 of which was 1*08 



Sugar 1680-6 



Tartaric acid 7*7 



Gluten 505 



Cream of tartar 18'5 



Alumina 3'0 



Lime 2'0 



Magnesia 2"0 



1764-3 



According to this table, gluten and no albumen is 

 found in the plant, hence there is about one-thirtieth 

 of gluten to the quantity of sugar, and this, reckon- 

 ing that from 13 to 30 per cent, sugar exists in grape 

 juice, would give from 1 to \ per cent, gluten. 



Thenard appears to have detected gluten in the 

 juice of the Johannisberg grapes ; at least he found in 

 it a sticky albuminous body, which, when exposed to 

 the action of heat, presented all the appearances of 



* Jahrh.fur pr. Pharm. Bd H, s. 327. 



D 



