138 OIL. 



M. Matthew de Dombasle made some comparsiive experiments a. 

 Roville on the cultivation of oleaginous plants. The results obtain- 

 ed by this skilful agriculturist are much less favorable than those of 

 M. Gaujac. Instead of 19 cwt. and 15 lbs. of colewort seed yield- 

 ing 875.4 lbs. of oi; per acre, M. de Dombasle only obtained 11 cwt. 

 2 qrs. 21 \h§. yielding 392.3 lbs. of oil ; and the other kinds of seed 

 in proportion. But as I have said already, the fertility of the soil, 

 and the labor and pains bestowed upon it, may have contributed to 

 the differences observed, because here the influence of climate may 

 be overlooked. There is one circumstance, however, which may 

 explain the great differences in the quantity of oil obtained, which 

 is the perfection of the press employed to extract it. In a general 

 way oil-presses are so imperfect that they all leave a quantity of oil 

 more or less in the cake. 



Here are two examples : from 2765 lbs. avoird. of fine colewort 

 seed, gathered in 1842, and weighing 52^ lbs. per bushel, I obtained : 



lb«. 



Of oil 1130.5 



Of cake 1384.9 



Loss 249.6 



2765.0 



In Other terms, per cent. : 



Oil 40.81 



Cake 50.12 



Loss 9.07 



iooioo 



but by a careful analysis of the same seed in the laboratory, 50 per 

 Dent, of oil was obtained. 



2d. In 1840 and 1841, I made some experiments on the cultiva- 

 tion of the madia sativa, intermixed with carrots in a fertile soil, 

 well manured with farm dung. The crop of the year 1840 was ex- 

 cellent ; it required one hundred and twenty-seven days to come to 



maturity. 



ibi. 



Seed, husks deducted 2424 



Dried leaves employed as litter 7700 



Carrots without their leaves 31966 



The seed gave : 



Of oil 635.8 



Of cake 17067.6 



100 of seed gave : 



Oil 26.24 



Cake 70.72 



Loss 33.4 



100.00 



These results agree pretty nearly with those which have been 

 published by ether agriculturis s ; but the seed of this madia, which 

 in the press gave 26.24 of oil per cent., actually yielded 41 per cent, 

 by analysis in the laboratory ; this difference between practical re- 

 suits and those of the laboratory, shows us how large a quantity of 

 oil is generally left in the ;ake. When the cake is used for feeding 



