RECORDS OF MEETINGS 285 



SECTION OP ASTEONOMY, PHYSICS AND CHEMISTEY 



2 October, 1916 



Section met at 8 :30 p. m.,, Vice-President Ernest E. Smith presiding. 

 The following program was presented : 



Lucius P. Brown and A Promising Chart for Detecting Adul- 

 C. V. Ekroth, terated Samples of Milk. 



Chaxles Baskerville, Colloids in Their Eelation to Animal 



AND Vegetable Oils. 



Summary op Papers 



Mr. Brown and Mr. Ekroth stated that as the result of investigations 

 of published analyses of over 200,000 samples of milk a chart has been 

 devised which appears to show the approximate limits of the chemical 

 composition of normal cows' milk as concerns the fat and solids-not-fat 

 and the inter-relation of these two. This chart should be capable of use 

 as an indicator of adulteration in milk if the fat and total solids only 

 are known. The inter-relation of the fat and solids-not-fat appears to 

 indicate that almost all the milk standards as made by law in the several 

 states of the Union, as well as that adopted by the Federal Government, 

 are unbalanced and not based on the actual enforcement. Further, in 

 legislating on this subject, that fat and total solids should be specified, 

 because the figure for the total solids necessarily includes the fat and 

 the very considerable range of limits in the fat percentage corresponding 

 to any given figure for the solids-not-fat would allow of the abstraction 

 of a considerable proportion of the fat without placing the milk in the 

 adulterated class. 



The accuracy of this chart has 'been shown by testing it against the 

 experience of New York City for the past 10 years. A plotting of the 

 composition of milk, as shown by analysis for this period, indicates an 

 agreement between the percentage of fat and solids-not-fat, which is in 

 accordance with expectations as shown by this chart. 



Dr. Baskerville stated that animal and vegetable oils extracted from 

 selected and perfectly clean parts are usually neutral and ''"sweet". Com- 

 mercial exigencies result in the actual production of oils usually acid 

 and always contaminated. It is therefore necessary to refine the oils, 

 especially if they are to be used for edible purposes. The kinds of im- 

 purities, various but classifiable, and the favorable conditions of their 



