12 



upon being stirred in, chills the mixture and neutralizes much of the heat that is 

 freed by the crystallizing fat. 



In the Wolfbauer method the constant stirring keeps the temperature uniform 

 throughout the mass, and there is no sudden cooling such as is unavoidable in the 

 Dalican procedure. The lower the titer point the more noticeable are these 

 differences. 



I would therefore recommend the Wolfbauer method of stirring as giving results 

 nearer the true titer point. 



Unfortunately the method, in the writer's opinion, is trying and tedious, but from 

 the results obtained no hesitancy is felt in recommending the adoption of the Wolf- 

 bauer method of determining the titers. 



J. E. Weber finds that the method of saponification has no influence 

 on the titer, but thinks that the Wolfbauer method of stirring is the 

 more reliable for all kinds of titers, and gives his reasons as follows: 



The Dalican method was found easy to handle, because it gives definite instruc- 

 tions as to when to start and stop stirring; the Wolfbauer method leaves more to 

 individual judgment, but these difficulties are very slight for an experienced chem- 

 ist. While the Dalican method is reliable for the two harder stocks, it became less 

 so for the others and caused some difficulty, even with the cotton-seed oil. By experi- 

 ment it was found that for very low titers this method gives no definite result and 

 can not be used at all. We have to determine all kinds of stock and titers, and often 

 must use ice, and even ice with salt, during the determination. The Wolfbauer 

 method (with our modification) never fails us. It is true with very low titers, 1.5 

 or 2 C., that the duplicates are not so very sharp, but are still within 0.5. Put- 

 ting aside all speculations as to what the titers especially the low ones mean, the 

 Wolfbauer method gives comparable figures for low and high titers, and that is what 

 the trade needs and is demanding. 



This desire to get comparable figures resulted also in increasing the diameter of 

 the titer tube. A tube 1 inch in diameter does not give definite results with very 

 low titers; therefore the extra tall beaker (5 ounces) of the trade was chosen, the 

 average diameter of which is about 45 mm. The larger amount of fatty acids cools 

 off more slowly, giving the thermometer more time to become stationary and rise, 

 and it is possible to get a titer of 1.5 C. We have adopted this beaker for all the 

 titer work, its only disadvantage being that more fatty acids and larger samples of 

 stock must be used. 



To determine the influence of the larger volume of fatty acids, we determined the 

 titer of tallow fatty acids (from our stock) in three different tubes or beakers. 

 Each figure in the following results is the average of two determinations: 



42.325 in tube 25 mm diameter (Wolfbauer). 



42.425 in beaker 45 mm diameter. 



42.575 in beaker 70 mm diameter. 



Evidently there is an increase in the titer along with the increase of the diameter, 

 but it is small and of no importance. The 25 mm tube can not be used for very 

 low titers, the 45 mm gives satisfactory results and is also easy to handle, while the 

 70 mm beaker is very unhandy. 



R. D. Oilar, in Table X, shows to what an extent the diameter of 

 the tube affects the titer. The Dalican method seems less affected b} r 

 the diameter of the tube than the Wolfbauer. 



