THE VOLATILE PART OF PLANTS. 47 



nitrogen, the above samples, together with one of wheat-straw fiber, 

 analyzed by Heimeberg, exhibit the following composition, compared 

 with pure cellulose. 



Bye-straw fiber. Flax fiber. Wheat-straw fiber. Pure cellulose. 



C 47.5 41.0 45.4 44.4 



H 6.8 6.4 0.3 6.2 



45.7 52.6 48.3 49.4 



100.0 100.0 100.0 100.0 



Fr. Schulze has proposed (1857) another method for estimating cellu- 

 lose, which, though troublesome, is in most cases more correct than the 

 one already described. Kiihn, Aronstein, and H. Schulze (Henneberg's 

 Journal fur Land n-i rth^'huft, 18W>, pp. 289 to 297) have applied this 

 method in the following manner : One part of the dry pulverized sub- 

 stance (2 to 4 grams), which has been previously extracted with water, 

 alcohol, and ether, is placed in a glass-stoppered bottle, with 0.8 part 

 of potassium chlorate and 12 parts of nitric acid of specific gravity 1.10, 

 and digested at a temperature not exceeding 65 F. for 14 days. At the 

 expiration of this time, the contents of the bottle are mixed with some 

 water, brought upon a filter, and washed, firstly, with cold and after- 

 wards with hot water. When all the acid and soluble matters have 

 been washed out, the contents of the filter are emptied into a beaker, 

 and heated to 165 F. for about 45 minutes with weak ammonia (1 part 

 commercial ammonia to 50 parts of water); the substance is then 

 brought upon a weighed filter, and washed, tirst, with dilute ammonia, 

 as long as this passes off colored, then with cold and hot water, then 

 with alcohol, and, finally, with ether. The substance remaining con- 

 tains a small quantity of ash and nitrogen, for which corrections must 

 be made. The fiber is, however, purer than that procured by the other 

 method, and the writers named obtained a somewhat larger quantity, 

 by J to li per cent. The results appear to vary but about one prr ''/</ 

 from the truth. The observations of Kimig (Vs. St. 16), and of Hoffmeis- 

 ter(Vs. St. 33, 155), show much larger differences in favor of Fr. Schulze's 

 method. 



Hugo Miiller(Die Pflanzenfaser, p. 27) has described a method of ob- 

 taining cellulose from those materials which are employed in paper- 

 making, which is based on the prolonged use of weak aqueous solu- 

 tion of bromine. 



Trials made on hay and Indian-corn fodder with this method by Dr; 

 Osborne, at the author's suggestion, gave results widely at variance 

 with those obtained by Henneberg's method. 



The average proportions of cellulose found in various 

 vegetable matters, in the usual or air-dry state, are as fol- 

 lows : 



AMOUNT OF CELLULOSE IX PLANTS. 



Per cent. Per cent. 



Potato tuber 1.1 Red clover plant in flower 10 



Wheat kernel 3.0 " " nay 34 



Wheat meal 0.7 Timothy ' 23 



Maize kernel 5.5 Maize cobs 38 



Barley " 8.0 Oat straw 40 



Oat " 10.3 Wheat" 48 



Buckwheat kernel 15.0 Rye " 94 



