126 



Besana* examined 114 samples of butter from December, 18S7, to 

 April, 1888, which came from 30 differeut Italian provinces and repre- 

 sented 96 different dairies. The results ranged from L*1.8 to 30.19 c. c. 

 tenth-normal alkali for 5 grams butter fat (Reichert-Meissl-Wollny 

 method). 



Nilsont made experiments extending over one year with 15 cows all 

 of the same breed, which were fed rye, beets, and hay. The volatile 

 acids ranged from 9.27 to 20.5 c. c. tenth-normal alkali per 2.5 grams 

 of butter fat (Reichert figures). Nilson claims that the content of easilj- 

 melted glycerides and the qualities of the butter fat accompanying this 

 are not dependent on the feeding, but that the differences between sum- 

 mer and winter butter are due rather to the fact that at the time when 

 cows are feeding on ]iasturage and green fodders they are more likelj" 

 to be in the first stages of the milking period. 



In opposition to this belief are the investigations of Adolf Mayer,t 

 whicli indicated that not only the lactation period, but also beyond 

 doubt the food had a marked iiitluence on the volatile acids of the 

 butter. Spalhin»ani§ came to the same conclusion from his studies of 

 butters from <lifferent sections of Italy. 



The author's original ]>lan was to have samples of butter sent him 

 every 2 weeks from reliable sources in each province of Holland, accom- 

 panied by statements regarding the number, age, time since calving, 

 and breed of the cows from which the butter was made, and the food they 

 received, lie hoi)ed in this manner to secure data wliich would enable 

 him, with due reference to period of lactation and food, to fix limits to 

 the volatile fatty acids which would be of service in the critical exami- 

 nation of the butter. 



Although the original ])lan was not carried out in all its details, the 

 investigations were <juite extensive and are a valuable contribution to 

 the knowledge regarding Holland butter. 



The author's conclusions aie as follows : (1 ) The formation of volatile 

 fatty acids in the butter is dependent upon both the period of lacta- 

 tion and the food. (2) With the beginning of a new period of lac- 

 tation the content of volatile acids increases, and as the period 

 advances these acids diminish in quantity. With the beginning of the 

 pasturage season these acids increase, or at least are quite high; as 

 the season advances they decrease in amount. (3) On account of the 

 prevailing differences in the time at which the new period of lactation 

 begins, and of the influence of food on the amount of volatile fatty acids, 

 it becomes impossible to fix the limits of these acids either for the 

 different districts or for the different months of the year. (4) For the 



* Sui luethodi atti a distiugnere il burro artificialedal burro uaturale et le loco mis 

 celc. Wr^H. 



t Zcitsch. f. aiialyt. Chem., 1889, p. 179. 



tLandw. Vers. Stat., 'M (I88f<), p. 261. 



i Contributo alio studio degli acidi grassi volatili di Burro. 



