242 THE COMPLETE GRAZIER. BOOK n. 



establishments. A number of samples may be tested at once in the 

 machine, an illustration of which is given in fig. 50. The hand crank is 

 gradually brought to a speed of fifty revolutions per minute, and this is 

 maintained for three or four minutes ; then the crank is left free, and 

 the disk gradually brought to rest by gentle pressure with a cloth, after 

 which the tests may be read off on the tubes. A hundred samples of 

 milk may be tested in less than an hour, and the result is almost 

 independent of the individual skill of the operator. 



Machines of this kind are used, not only by wholesale purchasers of 

 milk for sale as milk, but also generally in creameries, in which milk is 

 purchased from dairy farmers to convert into butter. In Australia and 

 New Zealand the price paid for milk in many creameries is in proportion 

 to the percentage of butter-fat in each lot, and there is no doubt that 

 this is the most equitable method of purchase. 



Copious and long- continued lactation, wherever it occurs, is a natural 

 function for the most part artificially developed. It is, in fact, the 

 result of domestication of cattle, in the first place, by breeding and 

 training, but to some extent by soil and climate ; for it is found that 

 cattle in a feral state do not yield more milk, or yield it for a longer 

 period, than is necessary to give their offspring a good start in life. 

 The quality of milk is largely a question of feeding, treatment, and 

 climate, yet breed has more to do with it than all of these. We 

 see this demonstrated in the Jerseys and Guernseys more than in 

 any other breed of cattle ; the superior quality of their milk is 

 hereditary, and this heredity is no doubt owing to the care and tender- 

 ness with which these cattle have been treated for centuries, and to the 

 genial climate of their island homes. The Jerseys, more particularly, 

 exhibit the results of the influences mentioned, as will be seen from the 

 table of figures in the next paragraph ; and as these beautiful cattle 

 have been most carefully bred, fed, and tended for a long period, we 

 may accept the results as being conclusive in favour of careful breed- 

 ing, kind treatment, and a genial climate. Whether or not this qualtiy 

 of milking in the Jerseys will be perpetuated in the breed, in other 

 countries, and through succeeding generations, is a problem which 

 only time can solve, but so far it betrays no sign of falling off in the 

 United States, Canada, and elsewhere. All will depend on breeding 

 and treatment, no doubt, for in an}- case the quality is now hereditary 

 in the breed, and cannot be sacrificed save by unfavourable conditions. 



For some years past, at their annual Dairy Show in London, the 

 British Dairy Farmers' Association have conducted milking trials, 

 and the results have been very instructive. These trials have been 

 made in respect of quality as well as quantity of milk, and the 

 results are summarised by Mr. P. McConnell, in Part L, Vol. VI., of 

 the Journal of the Association, embracing a number of cows of different 

 breeds and extending over a period of ten years. The trials were 

 made by taking for analysis a sample of each cow's milk, at each 

 morning's and evening's milking on one out of two days of the show. 

 From the chemical data thus obtained calculations were made as to 



