Oct. 14. 1918 Chemistry of Sweet-Clover Silage 127 



The data in Table VI show that— 



(i) The amount of amino nitrogen in the alcoholic extract and in the 

 water extract is practically the same for the matured silage. In silage 

 from I to about 2 weeks old the water extract shows the presence of a 

 larger amount of amino nitrogen. 



(2) The amount of amino nitrogen in the silage made from alfalfa is 

 notably larger than that in the silage made from sweet clover. 



(3) The amount of amino nitrogen in the silage made from sweet 

 clover alone is practically the same as that in the silage made from sweet 

 clover and corn meal. The addition of corn meal does not have any 

 apparent influence on the amount of amino nitrogen produced. 



TITRATIONS WITH INDICATORS 



Titrations with indicators were made as follows: Twenty-five cc. of 

 the extract were pipetted into a flask with 200 cc. of carbon-dioxid-free 

 water, and 25 cc. of formalin added (i part of 40 per cent formalin to 

 2 parts of carbon-dioxid-free water). This had been made neutral to 

 thymolphthalein with sodium hydroxid. The mixture was well shaken 

 and allowed to stand for 15 minutes, when it was titrated to a distant 

 blue with A^/20 sodium hydroxid, using 5 cc. of thymolphthalein as 

 indicator. The total number of cubic centimeters obtained in this titra- 

 tion less the number of cubic centimeters used to obtain the acidity to 

 phenolphthalein represents the number of cubic centimeters obtained 

 in this titration less the number of cubic centimeters used to obtain the 

 acidity to phenolphthalein represents the number of cubic centimeters 

 due the titrable nitrogen. The figures as obtained are given in the A 

 column of Table VII. 



From the figures given in Table VII must be subtracted the figures for 

 the acidity titration given in Table III. The remainder represents the 

 amount of acidity due to the titrable nitrogen. These differences are 

 given in the B columns of Table VII. These differences multiplied by 

 0.7 give the weight of titrable nitrogen. The results are given in the C 

 columns. A comparison of the results in Table VI with those in VII 

 shows that the results obtained by the electrometric and colorimetric 

 methods are essentially the same. A direct comparison between the 

 results on the water and the alcoholic extract, colorimetric titration, is 

 given in Table VIII. 



