24 



JOURNAL OF THE 



34.70 I 65.30 



From Na20 



treatment with 



acid 1.1 29.10 5.60 



2.' 28.20 .90 

 3. 27.81 ! .39 



27.32 



.49 



33.92 66.08 \\ 28.78 



28.33 5 59 ' 25.59 



27.60! .73 h 24.79 



27.25 I .35 [ 23.91 

 26.78 .47 



71.22 

 3.19 



.80 

 .88 



28.34 71.66 

 25 38 ; 2.96 

 24.73 1 .65 

 24.08 I .65 



The time of contact with acid was about 40 minutes, wiiich 

 makes a difference of nearly .02 per cent, of fiber for every min- 

 ute of treatment with acid. 



Ladd (5th N. Y. Ex. Sta. Rep.) has shown that the degree of 

 heat employed causes a difference in results. The above work 

 shows that differences are also due to amount and to the con- 

 centration of the different reagents used, and to the time of con- 

 tact. To secure agreement in results, uniformity in all these 

 conditions must be attained. 



Granting this ^-an be done with different workers, the question 

 of accuracy of results confronts us. Without going into a review 

 of the work of different chemists bearii)g on this point, I should 

 like to call attention to the above tables under 4 and 5. One of 

 two conclusions must be drawn fi'om this work, viz. : 1st, That 

 if half an hour^s treatment with each alkali and acid is sufficient 

 to give the per cent, of crude fiber, then crude fiber is soluble in 

 both alkali and acid, and that to a somewhat considerable ex- 

 tent ; or, 2d, that if crude fiber is not soluble in these reagents, 

 then 6 treatments with alkali, and 3 subsequent treatments with 

 acid, are not sufficient to separate it. From either of these con- 

 clusions it is evident that the method lacks accuracy, and is at 

 best only a rapid method of rough approximation to the truth. 



6. Ash in the residue. 



Six .samples were taken for this : 



2 treated with alkali 45 minutes and acid 1 hour. 

 2 " *' " 1.] hours 



() H (( il tl (1 l( U 1 



(t 1 u 



In no case was any ash found in the residue. 

 7. Nitrogen in the residue. 



