On the Amount of Soluble Albumin in 

 Different Parts of Plants, 



BY 



H. Uno. 



While the seeds of most plants have been repeatedly the 

 subject of investigations in regard to their proteins, 1 the other 

 parts have served but rarely for such studies. 



It has long been known that the juices of plants on being 

 heated, often yield a coagulation of albumin. This is, however, 

 not due to the protoplasm present in all cells, since this is 

 insoluble in water, but it is due to reserve albumin which may 

 occur in the dissolved state not only in the cell sap but also in 

 t lie juice of the protoplasm itself. This albumin plays the role 

 of reserve material which may either be comsumed in the same 

 cells by their further growth, or after transportation into other 

 parts of the plants may be used for building up living matter 

 in the flowers, fruit or roots. 



It seemed to me that it would be of considerable interest 

 to ascertain which parts of the plants contain most of this 

 soluble reserve albumin 2 and I have therefore made a series of 

 quantitative determinations of it in roots, leaves and flowers. 



Of the subjects, in most cases, 50 grams fresh weight were 

 crushed with the addition of some sand in a mortar, and pressed. 

 The expressed residue was further washed with water, and 

 expressed once more. The filtered juices thus obtained were 

 heated, with the addition of some nitric acid, on the water bath 

 nearly to the boiling point and the precipitate formed was 

 collected on a weighed filter, dried at 100° C. and weighed. 



1 Cf. especially the publications of Ritthauscn and of Osborne and Campbell ; 

 further of Bokorny, Pfli'ig. Arch, 1900. 



2 The common, passive albumin alone is here considered. On the occurrence of 

 the labile, active albumin, see these Bulletins vol., II., Nos. 1 ; 2 ; 4. 



