of salad oils for the test as given by the New York Produce Exchange, 

 it would be a great saving of time. It seems to the referee that a 

 method in which the oil is allowed to remain perfectly quiet can never be 

 satisfactory. 



III. CONCLUSION. 



To sum up, it appears from the correspondence that it is practically 

 agreed that the cloud test and the cold test represent different methods 

 and do not furnish the same information, but, as Dr. Dudley says, there is 

 need for both tests; also, that the cloud test is suitable for salad oils 

 and for testing lubricating oils when the temperature at which they cloud 

 is desired, and that some modification of the flowing test must be used 

 for testing lubricating oils. The work thus separates itself into two 

 parts first, a study of a method for lubricating oils, and, second, a. 

 method for salad oils. 



As a basis, however, the following method for the cold test is offered 

 as a starting point. This is practically the one used by J. P. Millwood, 

 with a few added details suggested by the experience of others. 



COLD TEST (MILLWOOD). 



Warm the oil until all the stearin is dissolved and filter, through several thick- 

 nesses of filter paper, into a dry 4-ounce wide-mouth bottle, li ounces of the oil 

 to be tested; place in a freezing mixture and stir until the oil becomes solid, 

 then cork and' leave for one hour in the freezing mixture. Take the bottle from 

 the freezing mixture, wipe it dry, and place in a holder of ordinary magnesia, 

 asbestos pipe covering, or any suitable holder which will insulate the sides of 

 the bottle. The frozen oil is broken up and well stirred with the special cold- 

 test thermometer previously described, and at every degree rise in the tempera- 

 ture the bottle is inverted ; continue till the oil will run to the other end of the 

 bottle. The temperature registered at this stage is to be considered the cold test. 



The questions at issue on lubricating oils are 



1. Method to be used : 



(a) A flowing test ? 

 (I)} A clouding test? 



2. Preparation of oil for analysis : 



(a) Shall it be dried, and how? 

 (6) Shall it be filtered ? 



3. Method of cooling: 



(a) Shall it be stirred until solid ? 



(b) Shall it stand a definite time; and if so, how long? 



4. Method of melting : 



(a) Shall it be allowed to warm up at room temperature ? 

 (&) Shall it be warmed up in a bath ? 



As regards salad oils 



Can the cloud test be used for the testing of salad oils such as winter cotton- 

 seed oil ? 



Cooperative work along the following lines is requested for the pur- 

 pose of answering the questions enumerated above : 



