AGRICULTURAL CHEMISTRY AnROTECIT-NTY. 415 



added, the bnlyrouieter stoppered with a rubber, aud ceiitrlfngod for five min- 

 utes. The butyronieter is tlien placed in a water l)alh for five minutes at 60 

 to 70° C, tlie lieigbt of tlie fat colunm noted, and again oentrifuged for two 

 minutes. The second ceutrifugalization is not absolutely necessary, but is rec- 

 ommended. 



Tbe method requii'es about 35 minutes for its execution. 



A synthetic medium for the determination of colon bacilli in ice cream, 

 S. H. Ayers and W. T. Johnson, ju. {Abs. in Seience, n. ser., 30 {191J/), No. 

 1013), pp. 802, 803). — In a study of bacteria in ice cream an attempt was made 

 to prepare a synthetic medium for the detection of colon bacilli. "During the 

 experiments 53 difCereut combinations were tried. The most satisfactory nie- 

 (lium was made as follows: Agar, 1.5 per cent, asparagin 0.3 ])er cent, sodium 

 dibasic phosphate 0.1 i)er cent, lactose 1 per cent, and 2 per cent of a saturated 

 solution of litmus. The majority of the bacteria in ice cream did not grow on 

 this medium, while colon bacilli showed quite characteristic acid colonies which 

 with a Utile practice could be readily detected." The colon count in 43 samjtles 

 of ice cream was compared witli the estimated number from lactose bile tubes, 

 and in 41 the number determined on the nlates was higher than the estimated 

 number fi'om the tubes. 



Suspected colon colonies on the asparagin plates from 19 samples were picked 

 off aud inoculated into lactose broth fermentation tubes. From 10 plates all 

 the suspected colonies proved to be gas formers, while in the other 9 plates the 

 percentages ranged from 87.17 to 98.01. " This shows that it is possible to 

 detect quite accurately any colonies of gas-forming bacteria on litnms-lactose- 

 asparagin agar. A comparison of this medium with Eudo meilium showed that 

 the colon count on asparagin agar was much lower than that on the other 

 medium. We found, however, that in some cases at least it was impossible to 

 consider all typical colonies on Endo plates as colon bacilli. Certain strains 

 of liaciUus coli failed to give typical colonies on Endo plates aud acid and 

 peptonizing bacteria gave reactions similar to some of the colon strains. 



" It is evident that we have no entirely satisfactory method for the determi- 

 nation of colon bacilli, but it is believed that the use of synthetic media may 

 be developed to a point where it will be superior to other methods." 



The quantitative determination of added sodium chlorid in feeding stuffs, 

 A. Strigel and O. Handschuh {Landw. Vers. Stat., 83 (191.3), No. S-Jj, pp. 

 309-316).— Tests were conducted with the method (E. S. R., 32, p. 22) on a 

 large variety of feeding stuffs treated with sodium chlorid solutions. In one 

 series of tests the titration was done before filtering ofC the precipitated silver 

 chlorid and in the other after filtering. A sharp end point was obtained by the 

 second method. 



The use of bacterial nists of flaxseed for determining fiber and vraste of 

 flax stems, E. A. Domraciieva (Zhiir. Opytn. Agron. (Riiss. Jour. Expt. 

 Landw.), 1/f {1913), No. 3, pp. 155-166. figs. 5).— A rure culture of a bacterial 

 rust obtained from flax straw may be used for determining crude fiber and 

 similar substances in flax stems. The culture is first isolated from an infusion 

 of flax straw and then further propagated under anaerobic conditions on potato 

 overspread with chalk. The test is made in a tall glass cylinder of o cm. diam- 

 eter provided with a cork holding two glass tubes, one of which drops to the 

 bottom of the cylinder, while the other is short. The flax stems are placed in 

 the bottom of the cylinder and covered with boiling water. After a few minutes 

 tbe water is poured off and replaced by fresh water, the long tube is connected 

 with a steam generator, and the mass is sterilized for from 15 to 20 minutes 

 with steam. The flax stems are then infected with the pure cultures of rust 



