70 JOURNAL OF THE [July, 



NOTES ON THE STAINING OF CELLULOSE. 



BY E. G. LOVE, PH.D. 

 {_Read April loth, 1894.) 



Cellulose forms the basis of vegetable tissues, and also occurs 

 to a slight extent in animal membranes. It is composed of car- 

 bon, hydrogen, and oxygen, and its composition is the same as 

 that of starch. 



In chemistry the words cellulose and lignin are often used as 

 synonymous terms. It is preferable, however, to restrict the 

 word lignin, as is commonly done in microscopy, to those older 

 growths of the cell usually known as lignified or woody tissue, in 

 which the original cell has received secondary deposits, and has 

 as a whole been more or less changed in composition and reac- 

 tions from cellulose. 



Cellulose as it occurs in plant structures presents considerable 

 variety in physical properties. Sometimes it is soft, as in the 

 young plant, and again it is quite dense. This fact accounts for 

 the varying results obtained when cellulose is subjected to the 

 action of staining liquids. 



The staining of young and soft cellular tissue presents no 

 special difficulties, but when the cellulose increases in density the 

 difficulty is increased ; and this is true whether the cellulose is in 

 a nearly pure condition, as in the cotton fibre, or in the modified 

 condition of lignin or woody fibre. Stains which readily attack 

 young cellulose tissue have practically no effect upon it in its 

 maturer form. 



Some time ago I had occasion to make a series of tests on the 

 comparative value of several stains in the staining of cellulose and 

 lignin as found in textile and woody fibres ; and as the informa- 

 tion on this subject in the books is very limited, it was thought 

 that the matter might be of sufficient interest to bring some of the 

 results before the Society. 



It is of course important, in the staining of fibres for microscopic 

 examination, that they shall take the stain uniformly. In com- 



