Aug. 6,1917 Chemical Stvdies in Making Alfalfa Silage 285 



The results from bottles having a grade above 90 should manifestly not 

 be averaged with those having a percentage grade of 70 or less. 



Percentage op acidity in good silage. — ^With no supplement the 

 percentage of acidity in silage made from fresh alfalfa was 1.646; from 

 wilted alfalfa, 2.522 ; and from wilted alfalfa plus water, 2.302. Withsound 

 corn as a supplement, the average percentage of acidity in silage made from 

 fresh alfalfa was 2.387; from wilted alfalfa, 3.151 ; and from wilted alfalfa 

 plus water, 3.103. With germinated com as a supplement, the average 

 percentage of acidity from all bottles in silage made from fresh alfalfa was 

 2.807; from wilted alfalfa, 3.231, and from wilted alfalfa plus water 

 3.266. The smaller proportions of com used show a tendency to pro- 

 duce smaller percentages of acidity. This is shown by the individual 

 figures given in the tables. This statement holds for both sound and 

 germinated corn. 



With molasses as a supplement, the average percentage of acidity in 

 silage made from fresh alfalfa was 2.392; from wilted alfalfa, 3.282 and 

 from wilted alfalfa plus w^ater 3. 191. As with com, the smaller amounts 

 of molasses used produce a slightly smaller percentage of acidity. 



With rye as a supplement, the average percentage of acidity in silage 

 made from fresh alfalfa was 2.369; from wilted alfalfa, 2.509; from 

 wilted alfalfa plus water, 2.548. 



The silage from wilted alfalfa had in all cases a higher percentage of 

 acidity than the silage made from fresh alfalfa. The increase due to 

 wilting varies from about 15 per cent where germinated com was used 

 to about 50 per cent where no supplement was used. The addition of 

 water to the wilted alfalfa had a slight tendency to reduce the acidity. 



Percentage of acidity in bad silage. — The percentage of acidity in 

 bad silage varies so much that averages have little value. In general the 

 poorest silage had the lowest percentage of acidity, many samples of very 

 bad silage having an acidity value of about 0.5 per cent. 



Method of determining nitrogen in amino form. — The nitrogen 

 in amino form v»^as determined in the same solution used for the acidity 

 determinations, using the formol-titration method according to Sorensen, 

 as described by Jessen-Hansen.^ The method adapted to this work on 

 silage is as follows: To 25 c. c. of the neutralized alcoholic extract 

 representing 5 gm. of silage, were added 25 c. c. of a neutral solution 

 of dilute formaldehyde. In practice the determination of nitrogen in 

 amino form is made on the same portion of solution as used for acidity. 

 The formaldehyde solution was made by diluting one volume of 40 per 

 cent commercial formaldehyde with one and one-half volumes of water, 

 and making it neutral to phemolphthalein. After adding the formalde- 

 hyde, the solution was allowed to stand for 15 minutes, after which the 

 titration was made to a rose-red. In a previous paper ^ attention has 



* Jessen-Hansen, H. die Formoltitration. In AbderhaldEn, Emil. HA^fDBUCH der biochem- 

 ISCHEN ARBEITSMETHODEN. Bd. 6, p. 262-277, fig. 53. Berlin, 1912. 



' Sw ANSON, C. O., and Tague, E. L. a study op certain conditions which affect the activity 

 OF proteolytic enzymes in wheat flour. In Jour. Amer. Chem. Soc., v. 38, no. s. P- 1098-1109. 1916. 



