(580 EXPERIMETTT STATION RECORD. 



The average gain in weight per calf during the 3-day periods in whicli milk with 

 boric add was fed was 0.5 lb., milk with salicylic acid 3 lbs., with formaldehyde 

 5 Ibo., and milk with no preservative 1 lb. 



"The calves fed for an extended period with milk preserved with boric acid and 

 formaldehyde made very satisfactory gains in weight. The two receiving the boric 

 acid lost a good shart> of their haii-, presumaljly from the effects ut the acid." 



The eflfect of curdling with rennet upon the dig-estibility of milk, R. Popper 

 {Arch. Physiol. [Pflugcr], 92 {1903), No. 10-13, pp. (J05-(5i^) .— Artificial digestion 

 experiments showed that milk coagulated with rennet was somewhat less digestible 

 than untreated milk, but the author believes that the difference is not as marked as 

 has been claimed by some other investigators, since he found that there was a con- 

 siderable range in the results of parallel experiments. 



The digestibility of food consumed with varying quantities of water, S. 

 RuziCKA {Arch. ][i/(j., 4o {1902), No. 4, PP- 409-410).— The author was himself the 

 subject of experiments in which the digestibility of a mixed ration was determined 

 when a fairly large quantity of water was consumed at intervals during tlie day and 

 when practically the same amount Avas consumed immediately before, during, and 

 after meals. In each case the amount of water consumed daily was practically the 

 same, averaging nearly 1,480 gm. daily. The re.sults obtained showed that the 

 mixed diet was somewhat more thoroughly digested when the bulk of the water was 

 taken near meal times. The author believes that the results are not numerous enough 

 for general deductions, but that they do warrant the conclusion that a reasonable 

 amount of fluid taken at meal times can not have any bad effect. 



The digestibility of foods and condiments as shown by microscopical 

 studies of the feces, F. Sciiii.ung {Die Vcrdaulifhkeit dcr Nahrimgi<- und (jt'uva.wtiltel 

 uvf Grund iiiikroxlvpisclier Untersuchiiiigen der Faeces. Leipzig: H. Hariimg ifc Son, 

 1901, 2)p. 132, figs. 102). — Believing that the digestibility of different materials can be 

 most accurately determined by a microscopical examination of the iindigested resi- 

 dues, the author describes methods and reports results of a large number of such inves- 

 tigations. Some of the general conclusions follow: All foods which are not soluble 

 in water or rendered soluble by the digestive juices give larger or smaller amounts of 

 undigested residue. An abundant vegetable diet hinders the digestibility of animal 

 foods. There are no large undigested fragments from raw, finely chopped loin of 

 beef. When it is eaten with l)lack bread large muscle fibers are found in the feces 

 together with rye hulls. N'^egetable foods furnish the greater part of the feces. 

 When a mixed diet is eaten isolated starch cells are always found in the feces and 

 distended starch cells are regularly found, derived from the endosperm or the interior 

 of cereals, potatoes, and legumes, even if these materials were finely ground or other- 

 wise finely divided. The method of cooking, the mechanical condition of food, 

 habit, and regularity in eating are of the greatest importance in the digestion of food 

 and hence for the nutritive value of different materials under normal conditions. 

 Undigested residue from a given diet is generally excreted on the second day after 

 the food is eaten. INIechanical stimulation of peristaltic action is less important than 

 thei'nuc and chemical stimulation. 



On the causes, variations, and significance of the color of the feces, L. A. 

 Conner {Med. News, New York, 81 {1902), No. 9, pp. 400-403; ahs. in Jour. Amer. 

 Chem. Soc, 24 {1902), No. 11, p. 500).— The color of normal feces of adults on a 

 mixed diet is a l)rown of varying degrees of darkness. This color, while due in large 

 measure to the presence of modified bile pigment, is the result of a number of causes. 

 The elements which go to make up the color may be grouped as follows: (1) Digest- 

 ive secretions, (2) food residues, (3) discharges from the intestinal mucous mem- 

 brane, and (4) accidental ingredients, such as drugs, etc. 



Observations on vegetable proteolytic enzyms, with special reference to 

 papain, L. B. Mendel {Amer. Jour. Med. Sci., 124 {1902), pi>. 310-3 IS).— The 



