.'MG Oat and Tare Silage 



wide-necked bottles of about 1200 c.c. capacity. To the material was 

 then added 500 c.c. of distilled water (previously boiled and cooled) and 

 the bottle was sto])|)ered with a rubber bung and vigorou.sly shaken in 

 a shaking machine for four hours. The resulting dark brown coloured 

 extract was filtered first through musHn. the residual material being 

 well squeezed out. and then through a filter paper. 150 c.c. of the 

 aqueous extract was then made up to 500 c.c. with alcohol; this caused 

 the separation of a small amount of precipitate, which settled readily. 

 The clear liquid, which was slightly yellow in colour, was then filtered 

 oil' through a dry filter paper and submitted to analysis by means of 

 the Foreman alcohol titration method. 



The amounts given in the following description of the method refer 

 to the analy.sis of the silage extracts; the determinations on the green 

 crop extracts were carried out on larger volumes, since the ingredients 

 to be estimated were only present in relatively small amounts in such 

 extracts. 



10 c.c. of the alcoholic li(|uid were diluted with .50 c.c. alcohol and 

 the solution was titrated with .V/10 NaOH in the presence of phenol- 

 phthalein. When the neutral jjoint was reached, 12 c.c. of a ne\itral 

 aqueous formalin solution were added, whereon the pink colour was dis- 

 charged and the addition of one or two drops of iV/10 NaOH was necessary 

 to restore neutrality. The total titre of ^V/IO NaOH gave a measure of 

 the total acid grouj)s, free and combined, in the extract. It is im])ortant 

 to remember that amino acids and amides of the asparagine type are 

 also included in this measurement. The small amount of alkali re<]uisite 

 to restore neutrality after the addition of formalin has been shown by 

 Foreman to be an indication of the amount of dibasic amino acids and 

 proline present in the solution. 



The titration method of Foreman also enabled the amounts of amino 

 acids and volatile bases in the extracts to be determined. To 50 c.c. of 

 the alcoholic liquid in a 500 c.c. distillation flask was added an amount 

 of iV/10 NaOH sufficient to produce neutrality. The contents of the 

 flask were then submitted to steam distillation, a vigorous current of 

 COj-free steam being passed through for about five minutes. The bases 

 with the alcohol were caught in 10 c.c. N jlO HCl which had ])reviously 

 been pipetted into the receiver. The excess of acid in the contents of 

 the receiver was determined by titration with iV/10 NaOH in the presence 

 of alizarin and the amount of acid equivalent to the volatile bases 

 estimated by dift'erence. The liquid remaining in the flask, which is 

 alkaline after the distillation owing to the hydrolysis of the salts of 



