666 



EXPERIMENT STATION RECORD. 



Carbohydrates in different food stuffs (iu dry matter). 



The author states that the discrepancy between the total carbohy- 

 drates and the nitrogen-free extract " is diminished by the later results, 

 but still exists to an extent which can not be overlooked." 



Method of determining the acidity of milk, A. Devarda {Milch 

 Ztg., 25 {1896), Mo. 49, p. 785, Jig. 1). — The apparatus used in this 

 method is called an acidimeter. It is a glass-stoppered flask of about 

 100 cc. capacity with graduated neck. One hundred cubic centimeters 

 of milk is placed in the flask, pheuolphthalein added and then decinor- 

 mal alkali added as in ordinary titration. At the end of the reaction 

 the amount of alkali added is read oft" on the graduated neck and the 

 acidity calculated. 



Several comparisons of this method with Soxhlet's method showed 

 that the two gave nearly identical results. 



Contribution to the knovrledge of the rancidity of fats, E. 

 Spaeth {Ztschr. anaUjt. CJtem., 35 {1896), p. -171). — The author worked 

 on hog's lard. He found that the fats on standing became rancid and 

 ascribed it to oxidation due to the action of light and atmosj)heric 

 oxygen, the unsaturated oleic acid being chiefly attacked, with the 

 formation of acids with lower percentage of carbon. Aldehyde bodies 

 and oxy-fatty acids were also formed. All the fats contributed to the 

 formation of free fatty acids, aud the volatile fatty acids increased 

 greatly with the increase of free fatty acids. The oxidized fats had 

 a lower iodin number and higher melting point than the fresh fats. — 



B. W. KILGORE. 



On the determination of stearic acid in fats, O. Hehner and 



C. A. Mitchell {Analyst, 21 {1806), Ike, p. 316-332).— The method, 

 which numerous trials on a variety of materials has indicated to be 

 quite reliable, is as follows: Prepare a supply of alcohol (methylated) 

 saturated at 0^ C. with pure stearic acid, or with stearic acid which 

 only contains traces of palmitic acid. Dissolve from 0.5 to 1 gm. of the 

 mixture of the fatty acids to be examined, if these acids are solid, or 

 about 5 gm. if fluid, in about 100 cc. (exact measurement is not neces- 

 sary) of the stearic-acid-alcohol solution. Leave iu an ice bath over 

 night, agitate next morning and allow to stand in ice for a short time, 

 tilter off while the mixture remains in ice, wash with stearic-acid-alcohol 



