358 Oat and Tare Silarje 



increase in the ether extract, whereas in bag 6, an ahnost equal i)ei- 

 centage destruction of nitrogen-free extractives was accompanied by a 

 35 per cent, increase in the amount of ether extract. 



The results obtained in this regard for bags 1 and 2 were curious. 

 In both bags the percentage loss of nitrogen-free extractives was about 

 19 per cent.; in bag 1, however, the increase of ether extract was 23 per 

 cent., the corresponding figure for bag 2 being only about 9 per cent. 

 As bag 2 occupied the ujjper half of the small silo, it is ])ossible that a 

 portion of the volatile organic acids escaped as a result of "heating," 

 since analysis of the extracts showed that the bag 2 silage was iiiuch 

 poorer in respect of volatile acids than was the bag 1 silage. 



In bags 7 and 8, where spoiling occurred, there was an appreciable 

 decrease in the amount of ether extract during ensilage. It follows that 

 where silage undergoes rotting, the process is attended by losses of ether 

 soluble material. It has already been demonstrated that the organic 

 acids are readily destroyed during the spoiling of silage by moulds. 



If the figures for the ether extracts be compared with those obtained 

 in the titration of the organic acids in the extracts, certain interesting 

 facts are disclosed which merit further investigation. The figures ob- 

 tained for the green crop extracts show that the green oats and tares 

 contained an appreciable amount of non-volatile material which titrated 

 with iV/IO NaOH in the presence of phenolphthalein. The amount of 

 volatile acidic constituent was negligible. The nature of the non-volatile 

 acidic constituent was not ascertained. It was observed, however, that 

 during titration of the green croj) extracts, a strong yellow colour de- 

 veloped, which intensified as the neutral point was approached. It is 

 probable tliat the oats and tares contain a constituent which reacts 

 with the soda producing the colour change, and the soda used up in 

 this reaction accounts for the high non-volatile acidic figure obtained 

 for the green crop. As this phenomenon was noticed in an equal degree 

 during the titration of the silage extracts, it follows that this constituent 

 escapes destruction during ensilage, and thus it is not feasible to cal- 

 culate the whole titration figure for non-volatile acidity in the silage in 

 terms of lactic acid. It was further noted that the spoiling of silage by 

 moulds occasioned the destruction of the constituent in question. 



The following table gives a comparison of the percentages of ether 

 extract in the dried silage samples with th(> iion-voIatile acidity calculated 

 as lactic acid, after subtracting from the uon- volatile acid titration 

 figure the corresponding figure for the green oats and tares. 



