198 



By the Reichert-Meissl process, we obtain only a certain fraction of the 

 total volatile acids and which is fairly constant if carried out under stand- 

 ard methods. 



To determine the relation of the volatile acids obtained from the R.- 

 M. process of distillation to the total volatile acids, distillation was made 

 with steam. By this means it is possible to estimate the total volatile 

 acids. The usual method of saponiflcation and precautions were taken as 

 in the R.-M. process. 



One thousand c.c. were distilled with steam and an alignment por- 

 tion titrated which gave a total of 6.03 per cent, volatile acid as butyric 

 acid. In the R. M. process, 5.19 per cent, of acid was obtained from the 

 same butter fat. Thus we see that only 86 per cent, of the total per cent, 

 of volatile acids were obtained by the R. M. process. 



The Rate at ichicJi the Volatile Ac4ds Distill hy Means of Steam. 



The same method was used as in the previous experiment in determin- 

 ing the total volatile acids. The distillation was collected in portions of 



50 c.c. and titrated with NaOH. Twenty fractions were titrated and 



10 

 the result shown in Table II. 



Table III. 



No. 



C. C. NaOH 



10 

 Per cent. vol. acid as butyric 



1. 



2. 



3. 



4. 



5. 



6. 



7. 



8. 



9. 



10. 



12.7 



8.48 



5.58 



3.66 



2.4 



1.52 



1.00 



.70 



.60 



.45 



2.03 



1.36 



.89 



.59 



.39 



.25 



.16 



.11 



.08 



.06 



11. 



.30 



.047 



No 12. 



N 

 C. C. NaOH .30 



10 

 Percent, vol. acid as butyric .047 



15. 



16. 



17. 



18. 



19. 



20. 



.20 



.18 



.15 



.14 



.13 



.10 



.03 



.028 



.023 



.022 



.021 



.017 



Total 



38.74 



6.22 



The weight of butter fat taken for the experiment as shown in Table 

 II was 5.50 grams. The per cent, of volatile acid and distillate is based 

 on live grams of fat. 



From Table II it is seen that the first fractions contained the greater 

 part of the volatile acids, decreasing rapidlj- after the second fraction, and 

 that the volatile acids are practically all distilled when 1000 c.c. have 

 been collected. 



