38 EXPERIMETSTT STATION RECORD. 



"The gases of a silo are carbon dioxid and nitrogen, the carbon dioxid being evolved 

 by the intramolecular respiration of the ensiled tissues, while the nitrogen is simply 

 due to the entangled atmospheric air that is originally present when the silo is filled. 

 In good silage, where putrefactive changes do not occur, the gases associated with 

 bacterial fermentation are not found." 



First-class corn silage was made in numerous instances in small receivers, the tem- 

 perature of which never exceeded 75 to 80° F. The changes that characterize the 

 formation of good silage are considered due to the changes inaugurated and under 

 the more or less direct control of the protoplasm of the jjlant tissues that are ensiled. 

 It is concluded that the acids of silage are a product mainly of the intramolecular 

 resi)iration, and that the degree of acidity is dependent upon the duration of the res- 

 jjiration of the cells. These facts are considered as explaining the presence of large 

 amounts of acids in silage from immature and succulent crops. The putrefactive 

 changes occurring in silage are due to bacteria capable of developing under anaerobic 

 conditions in the succulent tissues. That the peculiar aroma of good silage can be 

 produced under conditions in which all vital processes are suspended is taken as an 

 indication that enzyms are operative in this connection. 



' ' The unavoidable losses in silage are due to the formation of water, carbon dioxid, 

 and volatile organic acids, which are produced as a result of the intramolecular res- 

 jiiratory processes of the ensiled tissues." 



The avoidable losses are due mainly to the decomposition of organic matter by l^ac- 

 teria and molds. The admission of air by imperfectly constructed silos facilitates the 

 growth of these organisms and prolongs the direct respiration of the plant tissues. 

 Bacterial acti\ity, instead of being essential, was found deleterious, being most marked 

 where putrefactive changes occurred. 



Unavoidable losses in silage, F. H. King {Wisconsin Sta. Rpt. 1900, pp. 189-196, 

 figs. 2). — The work here reported consisted of a series of experiments in the produc- 

 tion of silage with small quantities of different materials under the complete exclu- 

 sion of air, but permitting so much as would be entangled in the material when filling 

 the silo. The materials were ensiled in Mason jars. In the first experiment with 

 peas, cowpeas, oats, rye, and corn, all in a comparatively early stage of growth, the 

 results show the greatest loss in weight during the first 15 days on oats, rye stand- 

 ing second, and corn last. The loss on cowpeas was also small. The author con- 

 cludes that in 100 tons of corn silage under similar conditions the loss of dry mat- 

 ter would have been between 1.27 and 1.62 tons. In this first test the material 

 was not compressed sufficiently to crush the tissues and express the juices. In the 

 second experiment peas, cowpeas, oats, and corn were treated as in the first, except 

 that the plants were 27 days older. Alfalfa from 6 to 8 in. high was added to the 

 test. The materials were packed to have a mean weight of 33.6 lbs. per cubic foot. 

 The loss calculated on the green weight ranged from 0.91 per cent in 108 days of hot 

 summer weather for the cowpeas to 4.93 per cent for the corn, the average loss l)eing 

 2.71 per cent. The object of the third trial was to determine the effect of the close- 

 ness of packing on the losses, and the test was made with mature corn packed closely 

 and loosely, but the results obtained were not conclusive. In the fourth and ninth 

 experiments the gaseous products given off from the corn silage were measured. In 

 experiment 4 the corn was in the milk stage and in experiment 9 fully matured 

 when ensiled. In 105 days number 4 lost 3.31 per cent of its green weight and 

 number 9 3.24 per cent in 59 days. The total amomit of gas collected in experiment 

 number 4 was 20.10 cu. ft., and in experiment number 9 17.05 cu. ft., or from 3 to 4 

 times the volume of the silage. On the average 74.02 per cent and 72.24 per cent 

 of the gas given off by the silage in experiments Nos. 4 and 9, respectively, was 

 carbonic-acid gas. Experiment number 8 consisted in the measurement of gaseous 

 products given off from clover silage. On June 18 medium clover was packed so as 

 to give 22.5 lbs. per cubic foot in an air-tight iron cylinder. After 28 days it had 



