86 AGRICULTURAL EXPERIMENT STATION. [Jan. 



above with a short rubber tube carrying a pinch-cock, the 

 other connected by means of a rubber tube with a suction 

 pump. By alternately opening and closing the pinch-cock 

 while the pump is working, the last traces of alcohol can be 

 readily removed from the soap. 



Dissolve the soap thus obtained in 30 cubic centimetres of 

 warm water, decompose with 20 cubic centimetres of a 20 per 

 cent, solution of orthophosphoric acid, distil off the volatile 

 acids through a condenser, filtering the distillate, and titrate 

 with decinormal sodium hydrate, using phenolphthalein as 

 indicator. The volatile acids are expelled from the flask by 

 a current of steam. When the distillate amounts to 500 

 cubic centimetres, the operation is considered to be complete. 

 The volatile acids are calculated as butyric. 



The condenser and connections are rinsed back into the 

 flask with boiling water, and the non-volatile acids washed 

 with hot water, and filtered when cool through the same filter 

 that was used for the distillate. The washing is contiriued 

 until no traces of phosphoric acid are left in the distillate. 

 The filter is then exhausted with hot alcohol, allowing the 

 solution to run into the flask. The alcohol is driven off on 

 the water bath, and the non-volatile fatty acids dried at 100° 

 C. in the air bath until they begin to gain weight. 



5. Some General Remarks on Analysis of Fodder and, 

 Fodder Analyses. 

 The application of an intelligently devised system of 

 chemical tests, for the purpose of ascertaining the amount 

 and the relative proportions of the essential proximate con- 

 stituents of our fodder articles, has rendered valuable ser- 

 vices to practical agriculture. The chemical analysis of 

 plants during their successive stages of growth has shown 

 marked alterations in their composition, as far as the absolute 

 amount of vegetable matter, as well as the relative propor- 

 tion of the essential plant constituents, are concerned. It 

 has rendered not less conspicuous the important influence 

 which the soil in its varying state of fertility exerts on the 

 quantity and the quality of the growth raised upon it. The 

 lessons derived from this source of information have stimu- 

 lated inquiries concerning the safest modes of manuring, of 



