10 



These results show that the same titer is. obtained, no matter how 

 the fatty acids are dried, on remelting, and that the fatty acids dried 

 by filtering and diying on the water bath give the same titer as when 

 dried at 105 C. for four hours. 



Thomas Gladding argues strongly in favor of the Wolf bauer method 

 of stirring, as he finds it gives better results when there is a difference 

 in room temperature. He says: 



We find that on a high-titer fat when the crystallization takes place sharply and 

 rapidly there is but little difference between the two methods, but in fats of low 

 titers, where crystallization is sluggish, a very marked difference is found. This 

 difference is to be expected from the circumstances of the case. In a low-titer fat 

 the lower and outside layers in the test tube become practically solid, the crystalliza- 

 tion is there complete and all heat of crystallization is lost in these portions. We 

 now stir together this cold mass and mix it with the small portion of liquid fat in 

 the center of the test tube. It can not be expected that the heat given out by the 

 slow crystallization of this small fraction will be sufficient to overcome the loss of 

 heat by radiation and at the same time raise the temperature of the portions that 

 have sunk several degrees below the titer point. This method is unscientific, inac- 

 curate, and certain to give results from 0.5 C. to 1 C. below the true titer point. 



It is urged most strongly by Mr. Gladding that the Dalican method 

 be modified by the adoption of the method of stirring used in the Wolf- 

 bauer procedure. In further support of this method he gives the fol- 

 lowing experiments made in February, at different temperatures, in 

 one case in the laboratory room and immediately afterwards in a cold 

 room, to ascertain the effect of varying temperatures upon the titer 

 test: 



TABLE VII. Comparison of effect of temperature in connection with different methods of 



stirring (Gladding}. 



In commenting on these results Mr. Gladding says: 



It will be seen that while temperature makes a marked difference in the results 

 when using the Dalican method of stirring, but little if any difference is found at 

 different temperatures when using the constant stirring method. This result might 

 be expected. When the mass is stirred constantly it begins to crystallize through- 

 out the whole body at a few tenths below the true crystallizing point. The whole 

 mass is of a uniform temperature, and the heat given out by the crystallization is 

 sufficient to overcome the loss of radiation, regardless of moderate differences of out- 

 side temperatures, and to secure at the center of the test tube the true crystallizing 

 or titer point. 



