386 



On the Composition of the 



in which advantage has been taken of the more refined and 

 accurate methods of investigation with which modem chemistry 

 has made us acquainted. 



The parsnips and carrots analysed were grown on the farm 

 attached to the Royal Agricultural College, in the calcareous, 

 rather stony, and by no means deep soil. 



Carrots, as well as parsnips, succeed best in a deep, well-pul- 

 verized, loamy ground, but in a shallow, stony soil they scarcely 

 reach half the size as when grown on a deep and sufficiently 

 porous loam. 



The soil in the neighbourhood of Cirencester on the whole is 

 not favourable to the growth of these roots, it being, in most 

 instances, too stony and too shallow. The roots for this reason 

 remain comparatively small, and 18 tons per acre are deemed a 

 good average crop of carrots in this part of the country. 



Before stating the results of the analysis of parsnips and 

 carrots, I sliall brielly describe the method which I followed in 

 determining the various constituents entering into the composition 

 of both roots. 



1. Determiaatioa of Water and Ash, — The quantities of water 

 and ash in the parsnip and carrot were determined by drying a 

 weighed portion of the roots, at first in the air, subsequently 

 at a gradually increased temperature, and finally in the water- 

 bath at 212° F. 



The loss in weight by calculation gave the percentage of water. 

 The dried substance was then burned in a platinum capsule 

 over a gas -lamp at a very moderate temperature. On account of 

 the large proportion of alkaline salts in carrots and parsnips 

 their ashes fuse readily. It is necessary, therefore, to apply in 

 the preparation of these ashes but a moderate temperature, be- 

 cause too intense a heat has the effect of fusing them. The 

 fusing salts surround particles of carbonaceous matter, and pre- 

 vent their complete dissipation by fire by keeping out the 

 atmospheric oxygen. 



In order to obtain a fair average sample for the water and 

 ash determinations, a whole root was cut into thin slices, from 

 which a portion was taken for analysis after having been well 

 mixed together. 



2. Determination of Cellular Fihre^ insoluble Protein Compounds, 

 and insoluble Inorganic Salts, attached to the Cellular Fibre. — By a 

 longitudinal cut a root was divided into two halves. One half 

 was reduced into a homogeneous pulp by grating it on a fine 

 grater. Of this pulp 1000 grains were digested with some cold 

 distilled water, and the liquid, containing in solution gum, sugar, 

 soluble casein, and other soluble matters, after some time was 



