Parsnip and White Belgiaji Carrot. 



387 



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 

 washings of the fibre, and allowed to settle in a glass beaker 

 for 24 hours. After that time the starch, which rendered the 

 water milky, was completely deposited at the bottom of the 

 beaker. The supernatant clear liquid was carefully passed 

 through a previously dried and weighed filter, into which the 

 starch was also transferred from the beaker. Being Avell washed 

 with distilled water, it was first dried between blotting-paper, 

 and finally in the water-bath at 212° F., and then weighed. 

 Carrots, at least those examined, do not contain any starch, and 

 the watery solution passing through the linen can therefore be 

 heated at once for the determination of casein. 



4. Determination of Casein. — The liquids from which the 

 starch was separated by the process just mentioned were heated 

 to the boiling point in a glass-beaker. 



Not the slightest precipitate was produced on boiling, thus 

 proving the total absence of soluble albumen, both in the carrot 

 and in the parsnip. 



A few drops of acetic acid were then added to the boiling 

 liquid, when a copious flaky precipitate of casein was formed. 

 This precipitate of casein was allowed to settle for 24 hours. 

 After that time the clear liquid above it was passed through a 

 weighed filter, on which the casein was also collected. The 

 precipitate was washed with distilled water as long as anything 



