12 COMPOSITION OF GEEEN EYE AND RAPE. 



These analytical results give rise to several observations : 



1. It will be seen that rape is much more nutritious than green 

 rye, and contains as large a proportion of flesh-forming constitu- 

 ents as the best kinds of food which are used in a green state. 



2. But not only is rape rich in protein compounds, but it con- 

 tains also a considerable quantity of oily or fatty matters. The 

 fatty matters extracted from rape by ether are semi-fluid, green 

 of colour, and possess a smell resembling the oil of rape-seed, with- 

 out being, however, so disagreeable as rape oil. 



It will be observed that the fresh leaves contain of these fatty 

 matters more than half a per cent, and the perfectly dry substance 

 about five per cent. So large a proportion of fatty matters, as 

 far as I know, does not occur in any other green food. The 

 occurrence of so considerable a quantity of fatty matters explains 

 at once, in an intelligible manner, the high fattening properties 

 which distinguish rape as a sheep-feed. 



3. Rape removes from the soil much potash, and next to it lime, 

 sulphuric and phosphoric acid, whilst, at the same time, the total 

 amount of inorganic constituents, or the ash of rape, is large. 

 It is for this reason that rape requires to be grown on good land, 

 or, at all events, on land in a moderate state of fertility. In poor 

 soils rape never comes to anything, and it is not worth the trouble 

 of cultivating. On land of moderate fertility, or on good rich 

 land, an occasional crop of rape, I am inclined to believe, would 

 supply the farmer with a larger amount of feeding materials than 

 is afforded in a crop of turnips grown under the same circum- 

 stances. Weight for weight, rape is richer in flesh-forming con- 

 stituents, and especially in fatty matters, than turnips ; and as a 

 crop of rape per acre is often heavier than- a turnip-crop, the cul- 

 tivation of rape, wherever it is advisable and admissible to intro- 

 duce it, can be confidently recommended. 



