260 MILK AND THE PUBLIC HEALTH CH . 



type, permit dust, dirt, and rain to get into the milk. Orr l 

 in his investigations paid special attention to the churns used, 

 and found considerable variation, especially in the form of lid 

 employed. He found five patterns of lids (types A to E 

 sketched below) in common use. Out of 45 noted, 8 per 

 cent were type A, rainproof and without ventilating holes ; 

 13*3 per cent type B with ventilating holes; 6'6 per cent type 

 C, i.e. funnel-shaped lid, unventilated ; 33*3 per cent type D, 

 funnel-shaped with ventilating holes; and 37*7 per cent were 

 type E, simple lids with or without ventilating holes. 



\ 



A. 



B. 



D. E. 



FIG. 18. Diagram of Type of Milk Churn Lids. 



Type A is the only pattern which is more or less satis- 

 factory, while types D and E, which comprise 71 per cent of 

 whole, and are apparently the prevalent types used in England, 

 are extremely objectionable. As Orr, referring more par- 

 ticularly to type E but applying nearly equally to type D, 

 says : 



Than this, a lid more calculated to allow contamination of the 

 milk could not possibly be designed. Dust accumulates in the 

 funnel-shaped portion, and either falls past the margin of the lid, 

 which generally fits badly, or is washed off with the milk discharged 

 from the cans. It is quite common for the milk to wash up over 

 the rim lid during handling, and to take up the dust on the top in 

 the process. During wet weather, any dust which escapes being 

 washed in by the milk in this way is carried into the can by the 

 rain. 



1 Report on Milk Contamination, 1908. 



