PRESERVATION OF MILK 387 



of trade preservatives, with the amounts recommended by the 

 vendors to be added to the different foods. As regards boric 

 compounds, the amounts recommended to be added to milk 

 varied from 1'2 to 14 grains per pint. The number of pre- 

 parations of formaldehyde sold under trade names was much 

 smaller than for the boric preparations, while the addition 

 recommended for milk varied from 1 : 32,000 to 1 : 82,000. 



Whatever may be advanced in favour of the addition 

 of preservatives to other foods, when added in definite and 

 declared amounts, the consensus of opinion is overwhelmingly 

 against their addition to milk. It is easy to understand why 

 many milk vendors favour their employment. Their use 

 converts a perishable article into a comparatively non-perish- 

 able one, allows surplus milk to be kept over until next day 

 without loss and be sold as fresh milk, and enables the 

 farmer and purveyor to neglect the necessary laws of cleanliness 

 in production. They are a further source of economy in that 

 they save the cost of cooling the milk. Preservatives are the 

 friend of the filthy dairyman. 



The essential objections to the addition of any preserva- 

 tives to milk are the following : 



(1) There is evidence that their consumption may be 

 directly harmful. The preservatives commonly added to 

 milk are admittedly prejudicial to the animal organism in 

 large doses. Boric acid and borax are given definite doses in 

 the British Pharmacopoeia. Obviously, then, the onus pro- 

 bandi is upon those who add them to food to prove that they 

 are harmless in small and moderate doses. It cannot be said 

 that their users have proved any such harmlessness ; they have 

 only failed to demonstrate deleterious effects in certain groups 

 of experiments. 



Very numerous investigations have been undertaken to 

 test their effect upon digestion, their action upon the digestive 

 ferments, and any prejudicial effects upon metabolism and the 

 functions generally of the body. Space will not permit these 

 investigations being discussed in detail, and the reader is 

 referred to the Departmental Committee Report and to the 

 Eeports of the investigations themselves. 



The generally accepted view is that while these substances 

 may possibly not be injurious in all cases, or even generally, 



