4 On the Composition of the 



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 tlie 

 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 Fibre, 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 

 strained through a piece of fine linen. The impure cellular 

 fibre remaining on the linen was washed with cold distilled 

 water until a drop of the washings ceased to leave a perceptible 

 stain, and evaporated on a piece of platinum foil. When washed 

 clean the impure fibre was dried in the water-bath, and its weight 

 ascertained. 



A portion of the dried impure cellular fibre was burned sub- 

 sequently in a platinum capsule, and by this means the propor- 

 tion of insoluble inorganic matters attached to the fibre was 

 ascertained. 



Another weighed portion of the finely-powdered and dried 

 impure fibre was burned in a combustion tube with soda-lime, 

 and the proportion of insoluble protein compounds contained in 

 parsnips and carrots, and obtained in the analysis with the im- 

 pure cellular fibre, was determined by calculation from the per- 

 centage of nitrogen furnished by the combustion of the impure 

 fibre with soda-lime. 



By deducting the amount of insoluble protein compounds 

 and inorganic matters thus obtained from the amount of impure 

 fibre the percentage of pure cellular fibre was ascertained. 



3. Determination of Starch. The milky liquid which, in the 

 case of parsnips, passed through the linen was mixed with the 



