846 EXPERIMENT STATION RECORD. 



TJe use of Koch s lymph in the diagnosis of tuberculosis in cattle, J. Nf.lson 



(Ncio Jersvij Stas. Ept. 1S93, pp. 209-2S5, d(jms. 5). — This article \va« printed as Bulle- 

 tin 101 of tlie station (E. S. K., 6, p. 332). 



Diseases of stock, R. R. Dinwiddie (Arkansas Sta. Bpt. 1SD4, pp. 1-22). — Arepriut 

 of HiiUetiii 25 of the station (E. S. R., 5, p. 995). 



Diseases of man and of domestic animals spread by dogs, O. Hknning {Agl. 

 Jour. Cape Colony, S {ISDo), Xo. 2, irp. 55, 56). 



Veterinary \A7^ork of the Mississippi Station (Mississippi Sta. Rpi. 1S93, pp. 43- 

 46). — Reference is made to publications of the station treating of anthrax or charbon, 

 diseases of sheej) and calves, dehorning, glanders, and colic. Prtnentive trciatnient 

 and symptoms of anthrax are discussed, and prescriptions to be used in the treat- 

 ment of cramp colic and wind colic are given. 



DAIRYING. 



Fluctuation in the volatile acids of butter fat, C. L. Penny 



(Delaware Sta. Bpt. 1893, pp. 183-191).— In tliis study the volatile fatty 

 acids were determined in samples of butter from a large creamery taken 

 at frequent intervals from September 16, 1891, to December 22, 1893. 

 During the first year the samples were kept some time, often a year or 

 more, before the volatile acids were determined. After that the sam- 

 ])les were saponified, usually on the same day the butter was made. 

 In all 118 samples were tested, and the results are tabulated, with the 

 averages by months. The changes by mouths are also illustrated by a 

 diagram. 



"Inspection of the table shows that the results vary greatly and very suddenly 

 within the same month, frequently much more than the averages of successive months ; 

 and the same mouth in 2 successive years shows wide differences probably due to 

 more permanent causes. There would seem to be no relation between season and 

 percentage composition of butter fat that is not overbalanced and entirely hidden 

 by other disturbing causes. But following the changes from month to mouth it will 

 appear that there is great uniformity of tendency. At certain times in the year the 

 percentage of volatile acids, whatever it may happen to be for the year and under 

 the particular circumstances, falls off rapidly, at other times it increases slowly and 

 again rapidly. The falling off in percentage of volatile acids appears to be rela- 

 tively abrupt. At a particular time of the year we can not say with any approxi- 

 mation to certainty what the proportion of volatile acids will be, but we may say 

 with some conlidence that at a certain season it will be increasing, at another decreas- 

 ing. From July to September in the year 1892 this proportion is quite different from 

 what it is during the same mouths of 1893, yet the rate of increase is substantially 

 the same and also the same as that found by Spallanzani.' From Septeniber there 

 is a rapid decline, continuing in our experience till October or November, in [Spallan- 

 zani'sj to December. There is then an almost continuous rise till June, when there is 

 an instant falling off to July. The two maximum points are September and J une, the 

 two minimum points from October to December, or late autumn, and July. The fact 

 that the results for the same month of different years vary so rather emphasizes these 

 tendencies. Then if the quality of butter improves with a higher percentage of vola- 

 tile acids, the best butter ought to be made in June and in September, the poorest in 

 July and in the late autumn. The minimum percentage in the above table is 21.77 

 on October 3, 1891, the maximum 32.23 on May 4, 1893. . . . The results are believed 

 to show as I'airly as may be the effect of season alone on the composition of butter- 

 fat. The extreme Huctuations here reported are naturally less wide than might be 

 i'liund between simples from different individual cows." 



» Staz. Sper. Agr. Ital., 32 (1889), March. 



