202 



Fermentation nt loircr temperature — Laeth- and aeetie ferments — 

 Derele>pment etf acidn in silage. — The fernient which induces the for- 

 mation of acetic acid in vinegar and that which canses the formation 

 of lactic acid in milk are l)oth active in the silo. Xeither of these 

 can grow in any known medium at a temperature above 47° C. 

 (117° F.). The most favoralile temperature for the former seems to 

 be about 38° C. (100° F.), and for the hitter, not above 33° C 

 (98° F.). Both ferments are aerobic. /. e., recjuiring an abundance 

 of air. Thus the formation of vinegar from sugar in a liquid kept in 

 a tight barrel is ?\o\\. l)ut when exposed to air. it goes on rapidly. 



Corn stalks as cut for silage contain a considerable amount of acid, 

 and this does not apjjear to decrease during the fermentation in the 

 silo. They also contain a considerable amount of sugar which is 

 changed to acids by ferments. The hot fermentation, however, pre- 

 vents acidity by making the mass more compact so as to exclude the 

 air which is necessary to the activity of the ferments. 



Sweet silage. — Silage, however treated, contains the acid originally 

 in the corn stalks. Sweet silage is that which has a relatively small 

 quantity of acid formed by fermentation. AVhat commonly passes 

 for sweet silage is not always the same thing. It may be obtained 

 either with or without heat. When slow filling of the silo with con- 

 sequent high tiMUj^erature is relied upon, the fermentations are very 

 different from those of the sweet silage obtained without heat. By 

 rapid filling and close packing, especially with the more mature and 

 dry corn, the mass ren.iains sweet, because little fermentation folloAVS. 

 When the fermentation is depended on for heat there is more loss. 



Results of chemical investigations. — In chemical examinations of 

 silage from Burr's AVhite and Burrill and Whitman corn, the volatile 

 acids sejiarated by distillation, and formation of their barium and 

 other salts, ranged from 0.397 to 0.080 per cent of the Aveight of the 

 silage. A rough quantitative determination of these acids in one 

 case gave about 70 per cent of acetic. 18 per cent of butyric, and 2 

 per cent of valeric acid, with other acids present in small quantities. 

 In another case a small quantity of lactic acid was found. ]\Iannite 

 also occurred. The non-volatile acids varied from 1.31 to 2.05 per 

 cent. Analyses of the gases in the silo revealed about 15 per cent of 

 carbonic acid and from 2 to 2^ ])er cent of oxygen. The remainder 

 w^as supposed to be mainly nitrogen. Analyses of samples of silage 

 from five other sources gave volatile acids ranging from 0.024 to 

 0.979 per cent, and non-volatile acids from 0.330 to 1.767. 



Field EXPr.Rnn-xTs with oats, 1888-89, T. F. Hunt, B. S. (pp. 

 194-213). 



1. Quantity of seed per acre. — Seven plats were sown two years wath 

 from 1 to 4 bushels per acre. 2. Compact or loose seed bed. — Four 

 methods of pre])aring the seed bed are compared, ranging from very 



