CHEMISTRY OF THE PAKSNTP. 13 



smell, but possessing a sweet agreeable taste. The nitrogen 

 compounds were also found to differ from the form they 

 usually assume in roots ; instead of existing as albuminous 

 matters, they are chiefly in the shape of "caseine;" and 

 the parsnip is further distinguished from the other root 

 crops, as carrots, turnips, &c., by having a larger propor- 

 tion of starch and a smaller proportion of sugar than the} r 

 possess. The composition of the root, too, varies in its 

 different parts; neither the heart of the root, nor its 

 external layers, where the starch is principally deposited, 

 contain so large a proportion of nitrogen compounds as 

 the portion between the two. The relative proportions 

 are thus given by Dr. Yoelcker : 



Heart. External Layers. ** "* 



Percentage of nitrogen compounds) 6>668 6 _ 493 9>375 



in the dried root, } 



The composition of the entire root in its natural state, as 

 used for feeding purposes, may be taken as follows : 



Compounds containing nitrogen, ... 1*280 



,, not containing nitrogen as oil, '546 



,, ,, starch, gum, &c., 7'170 



,, vegetable fibre, ... 8'022 



Ash (mineral matters), "932 



Water, 82'050 



100-000 



Comparing these constituents with those found in the 

 turnip, we see but little difference between their rela- 

 tive proportions of flesh-forming (nitrogen) compounds; 

 but of the heat-giving and fat-forming compounds, as 

 oil, starch, &c., the parsnip contains about double the 

 quantity, which renders it so particularly suitable as a 

 food for fattening purposes, or for milk-producing animals, 

 which require an analogous process in the vital economy. 

 The large proportion, too, of starch that the root contains, 

 is a point of some importance to the grower, as it at once 



