382 BOARD OF AGRICULTURE. 



creas digestion, and his experiments indicate that not only are the 

 gall and intestinal products wholl}' soluble in a pepsin solution, but 

 that the two methods will give very nearly- the same coefficients for 

 protein. 



Station experiments. In a previous part of this report are described 

 several digestion experiments with sheep, for the purpose of determin- 

 ingthe digestibility' of a number of cattle foods. These experiments 

 have given opportunit}' to secure additional information on some 

 points involved in a comparison of methods, and which bear upon 

 conclusions in regard to the digestibilit}' of food under certain 

 conditions. The following determinations were made: 



(1) The digestibilit}' of the protein of the several foods by arti- 

 ficial pepsin-pancreas* digestion. 



(2) The nitrogen extracted from the feces by successive treatment 

 "with alcohol, ether and water. 



(3) The nitrogen extracted from the feces, both fresh and after 

 drying, by digestion with a pepsin solution. 



Results with artificial pepsin-pancreas digestion. The table below 

 gives the percentages of protein digested from a variet}' of cattle 

 foods b}' this method. For a description of these fo3ds reference is 

 made to the "Analyses of Feeding Stuffs" in a former part of this 

 report. 



♦The pepsin solution used consisted of 5 grams of scale pepsin dissolved in one liter of 0.2 

 hj'drochloric acid. Two grams of the substance were digested for 24 hours (12 hours on each 

 of two consecutive days) in 250 c. c. of thii solution, hydrochloric acid (0.1 per cent) being 

 added at regular intervals uutil the solution contained 1 per cent. The undigested residue was 

 then washed thoroughly and submitted to digestion in a pancreas solution, made after a method 

 suggested by Dr. R. H. Chittenden of Yale College. (See Report Conn. Exp't tJtati n for 

 18S5, p. 45.) 



The sweet breads (pancreas) of neat cattle were finely cut and allowed to remain in a large 

 quantity of alcohol for a week or more. After the alcohol was strained off, the residue was 

 extracted with ether, dried, ground and bettled. To prepare the solution, 25 grams of the dry 

 pancreas, together with 2.5 grams of saUcylic acid and 250 c. c. of water were heated for 12 

 hours at 40 degrees C. The solution was then filtered, and the residue washed until the filtrate 

 and washings amounted to one liter. Two hundred c. c. of this solution were used in each ex- 

 periment, with 0.6 gram of sodium carbonate and a few drops of a solution ol 20 grams thjmol 

 in 100 c. c. alcohol. The digestion was continued for the same length of time as with the pep- 

 sin solution. 



