682 Summary of Agricultural Experiments, [nov., 



The conclusions reached from the butter tests were that cocoa-nut 

 cake produced a butter which gave a refractometer figure below the 

 normal, while the Polenske number was very high; the Reichert-Meissl 

 number was, however, quite normal. Feeding with linseed cake in- 

 fluenced the butter in respect to the Polenske number, butters from 

 this source giving a figure much below the normal; the refractometer 

 figure was also influenced, a distinct rise being noticeable. No very 

 great differences were shown in the texture and flavour of the two sets 

 of butter compared in this experiment. The butter from the cocoa-nut 

 cake, however, had as a rule a firmer and less oily texture and better 

 flavour than the linseed-cake butter. 



Colouring of Milk (Jour. Roy. Agric. Soc, Vol. 71, 1910). — This 

 experiment consisted in examining various samples of milk with an 

 apparatus known as a Tintometer, in order to determine the nature 

 of the colouring matter of the milk. By the aid of this apparatus it 

 is possible to ascertain the exact combination of dominant colours 

 (red, yellow, and blue) necessary to match a particular shade of colour I 

 in a sample of butter or milk, and to calculate, from figures on the i 

 coloured glasses used in the Tintometer, which are graded on the 

 basis of equivalent colour value, the percentage of black (combina- 

 tion of the three dominant colours in equal proportions) to either 

 orange or yellow. 



Three samples of milk were dealt with — (1) Devon, (2) separated 

 milk coloured with annatto to resemble the Devon milk, and (3) \ 

 separated milk not coloured. The milks for the purpose of examina- 

 tion were put into a tube graduated to show sections of milk of various 

 thicknesses. Red, blue, and yellow glasses were used in the Tintometer, 

 and the colours developed (whether black, orange, or yellow) by the 

 glasses are given in the report, together with the percentage of black to 

 orange and black to yellow colours. It is shown that the black in the 

 annatto colouring material used dies out as density increases, whilst | 

 the black in the milk increases in density under the same conditions. 

 The decrease of black percentage between the Devon and the coloured j 

 milk is stated to point to the use of a colouring material purer in 

 colour than the milk, whilst the increase in the percentage of black 

 in the separated milk when compared with the Devon is stated to be 

 what would be expected when the butter fat has been abstracted. It 

 is submitted that the experiment goes to show that colour measure- 

 ments by the Tintometer disclose (what cannot be determined by 

 ordinary vision) the presence of an added colour material to separated 

 milk. 



Diseases of Live Stock. 



Mortality among Calves (Harper Adams Agric. Coll., Supplementary 

 Bulletin to Annual Report, 1909). — This investigation was undertaken 

 to discover the cause of death among calves on a farm in Shropshire. 

 Not one calf had been reared on this farm since the tenant had been 

 in occupation, although calves brought in had thriven well. 



In all cases the symptoms were a weeping from the eyes from! 

 the second to the third day, continuing until the fourth or fifth day, 

 when it became almost purulent and inflamed the eyes. The animal 

 then became gradually weaker, losing flesh very rapidly, and continu- 



