196 



Some allowance must be made in the time factor, slight saponification 

 taking place before placing in the steam bath, also during the time of cool- 

 ing after removing the flasks. But it will be observed that this factor was 

 uniform for the 10 determinations. 



From the figures in Table I. no such variations are indicated as re- 

 ported. 



Some of the factors which influence the Reichert-Meissl No. 



Rate of distillation. 



Failure to remove alcohol (when used). 



Size of distilling flask. 



Absorption of carbonic acid and quantity of fat taken. 



All those factors are under the control of the operator and constant 

 results are obtained by observing uniform conditions. 

 Tlie rate of distillation of the volatile acid by the Reichert-Meissl process, 



also the rate of distillation of the volatile acids hy distillation with 



steam. 



In determining the rate of distillation of the volatile acids by the 

 Reichert-Meissl process, the distillate was collected in fractions of 10 c.c. 

 N 



and titrated with 



NaOH. 



10 



The number of cubic centimeters of 



N 

 10 



alkali required to neutralize 



each fraction are tabulated in Table II, also the per cent, acid calculated 

 as butyric acid based on five grams of butter fat taken. 



Table II. 

 Showing Rate of Distillation by the R. M. Process. 



No. 



C. C. NaOH 



10 

 Per cent. vol. acid as butyric. 



1. 



2. 



3. 



4, 



5. 



6. 



7. 



8. 



9. 



10. 



11. 



4.6 



4.2 



3.8 



3.4 



3. 



2.6 



2,2 



1.9 



1.5 



1.3 



1.0 



.81 



.74 



.67 



.60 



..3 



.45 



.38 



.35 



.2fi 



.23 



.17 



Total 



29.50 



5.19 



From Table II it will be seen that the first fraction of 10 c.c. of the 

 distillate contains 15.6 per cent, of the total volatile acid, uniformly de- 

 creasing to the 11th fraction, which contains only three per cent, of the total 

 volatile acid. 



