ANIMAL PRODUCTION. 273 



Per cent 

 Undetermined | including acids, pari of the mucilage of the water 

 extract, etc. |: 



Petroleum ether extract 056 



Sulphuric ether extrad 354 



Absolute alcohol extract 07 1 



80 per cent alcohol extract :;. 860 



Water extract 3. 387 



I rwing to a Blight discrepancy in the amounts of undetermined material calculated 

 by difference and by detailed figures for the several extracts, the sum of the results 

 is given is not exactly loo. Some of this undetermined material has ahead} been 

 divided into groups in the course <»t" the investigations reported, bul the author con- 

 giders that the most important question to be studied is the determination of the 

 nature of the hemieellulose — non-pentosans of the acid extract, and thehexosan I '.' land 

 Ugnic acid of the alkali extract. 



The heat of combustion of the original hay and of the residues from the different 

 reagents used in determining its composition is as follows, the figures being calculated 

 on an ash-free basis: 



Heat of combustion of ash-free timothy hay and Us constibuu nt parts. 



Cilleries. 



Original hay 5, 805 



Residues: 



From petroleum ether extraction 4, 722 



From sulphuric ether extraction 4,613 



From absolute alcohol extraction 4, 044 



From 80 per cent alcohol extraction 4, 629 



From cold water extraction 4, 666 



From dilute acid extraction 4,780 



From dilute alkali extraction 4, 444 



From chlorination 4, 118 



The author's comments on some of these energy values follow: 

 " Confining attention to the extracts that form large fractions of the entire hay. we 

 find that the dilute acid extract, composed chiefly of hemieellulose has a somewhat 

 higher value than that ordinarily assigned to polysaccharides, viz, 4, LOO to 4, 230 calories. 



II The value for the alkali extract is still higher. The value for the 'lignic acid' 

 has been computed from the percentages of dextrose, polysaccharid or pentosan and 

 albuminoids, allowing 3,762, 4, iso and 5,900calories for their respective heat values; 



the value thus deduced for the undetermined ash-free residue, 'lignic acid,' is 

 5,281 calories. 



" The heat value of the residue from the alkali extraction, crude fiber, is 4,368 

 calories without correction forash, or 4,444 calories withsuch correction. . . . 



"The heat value for the chlorination extract is very high. It must, however, be 



remembered that this value, obtained by difference, may be explained either h\ the 



low heat value of the chlorination residue or the high heat value of material removed 

 during chlorination. The former explanation appears the more probable, since the 

 chlorination process is distinctly oxidizing in its tendencies and the cellulose residue 

 has the properties in part of an oxycellnlose. Such an oxidation would naturally 



reduce the heat value of the residual organic matter." 



