159 



4. PROTEIN. 



Determine nitm-en by Kjeldahl or Gunning method in 10 cc of the 20 per cent 

 solution ami multiply by 6.38. 



5. LACTOSE. 



Dilute lOOccof the L'O pen-em solution in a 250 cc flask to about 200 cc; add 6 cc of 

 Fehlin</> copper Milphate solution and make up to the mark; filter through a dry 

 filter and determine lactose by the Walker method, boiling only two minutes with 



the I-'flllillL' solution. 



The method- for determining sucrose and fat be given further study. 



REPORT ON FOODS AND FEEDING STUFFS. 

 By FitKD \\ . MOUSE, Associate Referee. 



The request t" t'er >n cattle foods was unexpected and found me un- 



familiar with the nio-i recent work of the association on this class of materials. Noting 

 that ii \\a- n -. oinincndeii last year to continue the trial of the methyl pentosan deter- 

 mination after the method of F.llett. an attempt was made to simplify the method 

 before a.-kiuu- for cooperation from other members. \VTiolly satisfactory results have 

 not > i.tained, but it seems possible, with a little more time, to accomplish 



MII h a nullification. 



It was al.-> planned to compare the effects of the use of Ellett's method on some 

 lard cattle food alongside of a substance known to contain methyl pentosan. 

 For the latin- there was accessible plenty of t he sea weed, Fucus vesiculosis or rock weed, 

 ami a quantity was obtained, dried, and pulverized. For the standard cattle food, 

 wheat, bran was selected, since its content of pentosan is good, and Widtsoe reported no 

 evidence of methyl furfural in it by the qualitative tests. 



The method of procedure was to follow the provisional method for pentosan deter- 

 mination throughout and, after weighing the precipitated phloroglucid, to extract 

 with alcohol b\ Klletfs method of diu'i'sting the crucible and contents in a small 

 quantity of alcohol at 6-VM'., filtering, and repeating the operation until the filtrate 

 finally becomes colorless. A marked solubility of the precipitate was observed in 

 both cases. This was unexpected in the bran, and considerable time was spent in 

 'in- determinations. Results on bran varied much; but the seaweed gave rea- 

 sonably conei.nlant figures. By this time it was too late to send out samples to 

 other chemiata. Another |N>int was noticed in the prosecution of the work, namely, 

 that the provisional method for peniosans seldom if ever yielded furfural-free dis- 

 tillates when the pro. ri bed limit of volume was reached. The drops would still 

 show traces of furfural. 



Tlu-e jM.ints of di.-a-reement from published matter about the different forms of 



peniosans have convinced the referee that more work is needed on this provisional 



method in some of the details. There is an important field for research in our common 



lenaod the concentrated by-products in working out the constituents of the 



nitro-en-free extract. Most of the methods now in use are difficult of manipulation 



and more or less approximate in their results. Comparatively little attention is paid 



in , si nee the conventional methods of fodder analysis answer the practical feeder's 



purpose. 



vert Helen, progress in nutrition studies demands more attention to the less- 

 known carbohydrates, since their digestibility and consequent food value are unknown 

 quantities. 



The referee has no recommendations to make; but if no instructions are received 

 from the association it is his intention to continue the study of these newest methods 

 ot determining the less-known carbohydrates. 



