HAND-SEPARATORS. 153 



for use. Small motors, such as winches, only supply power, and 

 work scarcely cheaper than steam-engines. The conveniences and 

 advantages of their use do not more than counterbalance their 

 limited utility. They are, therefore, not to be recommended for 

 use in dairies. 



78. Hand -separators. Although hand -separators are admir- 

 ably adapted for use on a small scale, they are, on the whole, of 

 little importance for extended application. The best course to 

 pursue in the case of dairying on a small scale, in order to secure 

 the largest price for milk, to enjoy the advantages of wholesale 

 trade and capital, and to save time and labour, is the co-operative 

 treatment of milk supplied by many small cow -keepers, and 

 carried on in one place under competent direction. It is on this 

 account that the extended use of hand-separators, even in districts 

 in which there are excellent small independent farms, is only eco- 

 nomically justifiable so long as the erection of co-operative dairies, 

 for various reasons, is not advisable. Under certain circumstances, 

 they offer great advantages in small agricultural districts in the 

 neighbourhood of towns, and in small milk businesses carried on 

 in towns. In country agricultural districts they are employed 

 generally twice daily, viz. during milking. It is hardly necessary 

 to say that the separation should not be carried on in the byre, 

 but should be done in a clean room reserved for the purpose, and 

 supplied with pure air. The more carefully all precautions which 

 are advisable in the case of large separators are carried out, the 

 better will the return be for the large capital invested in them. It 

 is especially necessary in their case to maintain the prescribed 

 rapidity of the drum. 



79. The Separator Residue. On the inside of the separators, espe- 

 cially on the sides of the drums, there is always found, after they 

 have been in use, a dirty, slimy, highly-distasteful viscous mass, 

 the so-called separator residue or mud, which can often be taken off 

 as a skin in large pieces. It is quite erroneous to suppose that this 

 mass consists simply of the impurities present in the milk. No 

 doubt it contains all the solid impurities which have come into the 

 milk, small quantities of food, pieces of dung, hair, bristles, inorganic 

 mud, and many bacteria and other microscopic organisms. It is, 

 however, chiefly composed of the constituents of the milk, especially 

 the caseous matter, which forms about nine-tenths of the weight of 

 its dry residue. According to the season of the year, the weight of 



