652 EXPERIMENT STATION RECORD. 



Scliulze,' Avlio, working under Heuueberg's direction with l.^Jo per cent 

 and 5 per cent sulpliuric acid, came to the couchision that the 1.25 per 

 cent acid used in the Weende method did not dissolve any essential 

 amount of cellulose. Of 100 parts of cellulose taken, 99.17 parts 

 remained undissolved — i. e., the acid dissolved 0.83 per cent of the cel- 

 lulose. The 5 per cent acid dissolved 1.4G per cent of the cellulose, 

 and in the solution O.Gl per cent of the cellulose was recognized as 

 dextrose by Fehling's solution. 



In continuation of these experiments, G. Kiihu, Aronstein, and H. 

 Schulze" found that the cellulose of meadow hay, like pure cellulose, 

 (filtered paper) was slightly attacked by boiling with 1.25 jjer cent 

 sulphuric acid, but only an unimportant amount dissolved. Various 

 samiiles of hay, straw, and dung treated according to F. Schulze's 

 metliod (witli potassium chlorate and nitric acid) showed nearly the 

 same amounts of cellulose whether they had been ijreviously boiled 

 with 1.25 per cent sulphuric acid or not, although there were small 

 dift'ereuces noticeable, as shown by the following table: 



Cellulose detenuined by F. Svhulzea method. 



\ Without I Withpre- 



jprevious boil- vions boiliug 



iiig witli 1.25 witli 1.25 



jier ceutsul- i per cent sul- 



I pliuricacid. I pliuric acid. 



Clover hay 



Oat straw 



Dung from iiioadow hay. 

 Dung from oat straw. . . . 



The action of boiliug 1.25 per cent potassium hydroxid is quite dif- 

 ferent, as this dissolves important amounts of cellulose. Kern^ found 

 that while Swedish filter paper lost only 1 per cent by being boiled with 

 1.25 per cent sulphuric acid, the same paper when boiled with 1.25 per 

 cent sulphuric acid and 1.25 per cent potassium liydroxid lost 8.G per 

 cent. He concluded from this that paper cellulose was not noticeably 

 dissolved by dilute sulphuric acid but was dissolved by the subsequent 

 treatment with dilute ])otassium hydroxid. Without previous boiling 

 with sulphuric acid, 1.25 per cent potassium hydroxid dissolved only 1.7 

 per cent. 



Very similar results have recently been obtained by Suringar and 

 Tollens.^ Filter paper treated by the Weende method gave 92.49 to 

 93.96 per cent of cellulose. The same paper treated twice by the 

 Weende method gave 95.40 to 95.86 i^er cent of cellulose. Cotton 

 gave 88.18 to 90.8G per cent. 



1 Jour. Laudw., 7 (1865), p. 304. 



2 Jour. Landw., 8 (1866), i).293. 



3 Jour. Landw., 21 (1876), p. 19. 



■> Jour. Landw., 41 (1896), p. 343 (E, 



S. K.,8, p. 741). 



