VARIATIONS IN FAT ON STANDIN6. 169 



one pint was removed by dipping from the surface ; and each 

 portion was analysed (Table XXXIX.). 



TABLE XXXIX. — Vaeiations in Composition of Milk on 

 Standing (Pan). 



Here again it is seen that the milk does not remain practically 

 constant in composition for more than half an hour. 



Court of Queen's Bench Decision. — These figures were 

 obtained under conditions which need never occur in practice ; 

 indeed, the decision of the Court of Queen's Bench in the case of 

 Dyke v. Gower makes it necessary that they must not occur, as 

 it has been decided that a vendor is bound to sell milk in its 

 natural state ; it is equally an offence against the law to sell 

 milk which has been deprived of its cream by natural rising 

 when the milk is undisturbed, and to sell that wilfully adulterated 

 with skim milk. 



Practical Allowances for Fat Variation. — It is, however, 

 fortunately not a matter of extreme difficulty for a vendor to 

 comply with the spirit of this judgment : for instance, in the 

 sale of milk from a counter pan it is easy to stir the milk every 

 half hour, or, what is preferable, before serving each customer. 

 When milk is delivered in the streets the churn can be fitted 

 with one of the numerous arrangements for automatically keep- 

 ing the cream mixed ; the action of these is. too, materially 

 aided by the motion the milk receives from the movement of the 

 cart or barrow when drawn along the streets. A steady current 

 of about 1 foot per hour is enough to keep milk mixed, and, 

 exiept in very hot weather, milk is not churned by gentle stirring. 

 To ensure that the composition of the milk will not vary the 

 minutest fraction perhaps demands more skill and attention 

 than the average milk distributor possesses, but a practical 

 compliance with the judgment mentioned above can and ought 

 to be obtained. The author has calculated from a large number 

 of results that the probable variation of fat in milk due to cream 

 rising is only O'll per cent. 



