STUDIES ON FLAX RETTING. 



11 



separated mechanically with the destruction of other cell layers, as well as 

 the fatty substances, are lost in the last period of the retting. 



We summarize the principal results of our observations as follows. 



1. The greater part of cellulose remains unchanged after retting but 

 the small quantity which forms the cell-walls of cortical parenchyma, cambium, 

 phloem-parenchyma and epidermis is lost in the end of the last period. 



2. Pectin compounds which constitute the middle lamella of the fibers 

 and the cell- walls of cortical parenchyma, cambium and epidermis are dis- 

 solved almost completely at the end of the retting. 



^ 3. The quantity of protein is very small, so its loss is almost 



4. Tannin found in the contents of epidermal cells, diminishes gradually 

 in the process of retting and in the middle or in the last period it is dissolved 

 out completely. 



5. Lignin which forms the cell- walls of the xylem portion remains nearly 

 unchanged. 



largely dissolved out and only a trace is. found in the xylem portion, after the 



7. The quantity of the fatty substance lost during retting is very small,, 

 but a part of the cutin is separated at the end of the last period. 



HI. Chemical Studies. 



In order to obtain a definite idea as to the amount and nature of sub- 

 stances lost or changed during retting, we have made the following chemical 

 experiments. Along with these studies it seemed to us to be of practical 

 use as well as of much scientific interest to investigate the chemical nature of 

 gummy substances in the flax stem, since it has been shown that they are 

 the principal matters which suffer change during retting. 



