780 



Agriculture Abroad. 



[Nov., 



authorities on dairying*, and an account of their investigations 

 and conchisions was pubhshed in the issue of the Milchwirt- 

 schaftliches Zentralhlatt for 15th April, 1920. The results 

 suggest the possible value of the Hoyberg process as compared 

 with the Gerber process, althouoh it should be stated that 

 Hoyberg 's investigations are not yet complete. 



Each butyrometer in the Hoyberg process is filled with 

 9.7 cc. of milk, to which are added 3.4 cc. of one and 0.6 cc. 

 of a second fluid (both of secret composition) , carefully 

 measured, and the tube then closed with a rubber stopper. 

 The contents are mixed by turning the butyrometers five or 

 six times, shaking for J minute, and again turning as before. 

 The tubes are afterwards allowed to stand in a water bath at a 

 temperature of GO^ to 62*^C., stoppers uppermost, for 6 or 7 

 minutes, after which the previous operation of turning and 

 shaking is repeated. The butyrometers are finally again placed 

 in water, stoppers uppermost, for 8 to 10 minutes, and then in 

 a reverse position for a further period of 5 to 10 minutes. 



As a result of this treatment the fat is separated from the 

 rest of the milk. The amount can be read off on the graduated 

 scale. 



The whole apparatus and fluids can be packed in a well-fitted 

 tin box, which is easily portable. 



Tn the account given by the three investigators, the results 

 of five samples of milk so treated are tabulated, and it is shown 

 that they correspond very closely with those obtained by the 

 Gerber process. One-half of the milk used w^as preserved with 

 formahn (one drop to 50 cc. of milk), and the other half 

 cooled, and further tests were made on the following day. 

 These results showed differences in some cases up to 15 per 

 cent., and in one case (in the milk preserved with formalin) 

 20 per cent. Further tests with other samples of both whole 

 and thin milk were made later, and generally confirmed the 

 results previously obtained. 



^fr. Hoyberg mentioned the following three points with 

 regard to his process: — 



(1) Investigations are not yet complete as to w^hether the 

 process is suitable for milk from cows just calved, for milk 

 from dry cows, or other abnormal milks. 



(2) The process is unsuitable for skim-milk, as the results 

 given are too low. 



* B. Van der Burg, Professor of the Agricultural Higrh School of 

 Wagening-en ; W. Keestra, Director of the State Dairy School, Bolsward ; and 

 D. C. de Vaal. Director of the Cheese Central Station. Alkmaar. 



