OLEOMARGARINE. 139 



hours. It is seen that the ' oleo ' is not nearly as much emulsified as 

 the butter was at the end of one hour. 



u Fig. 6, PI. I, and fig. 3, PI. II, presents the same at the end of 

 twelve hours, which shows that the 'oleo' is but a trifle, if at all, fur- 

 ther emulsionized than the butter was at the end of the four hours. 



"It will be further noticed that the globules of butter are finer, 

 more uniform, containing very few large globules, and what is par- 

 ticularly conspicuous is the clearness and distinctness of the butter 

 globules. They are well defined, sleek looking, and have a clean-cut 

 outline which strongly intimates that they would go through an ani- 

 mal membrane which they are required to do, as will be seen later 

 on quicker than 'oleo,' which has a rough, coarse, ill-defined appear- 

 ance. This holds true until the whole is saponified. The best results 

 were obtained after exposing the fats to the digestive fluids for five or 

 six hours at a temperature of 100 F., then allowing the whole to 

 stand over night at a temperature of about 60 F. , and in the morning 

 adding an equal bulk of warm water. The butter then presents under 

 the microscope a most perfect emulsion. The globules are all very 

 minute, grading ofl' into almost imperceptible granules. 



"By examining the corresponding figures on the different plates the 

 comparative digestibility of the various fats and oils used in making 

 artificial butter may be seen. 



"That butyric acid does have some important role to play in the ali- 

 mentary canal is evident from the fact that sugar undergoes butyric 

 fermentation in the small intestines. Yeo says, in reference to this, 

 'Some of the sugar in the intestines, moreover, undergoes fermenta- 

 tion, by which it is converted into lactic and butyric acids. How much 

 of the sugar is absorbed as lactic and butyric acids has not been deter- 

 mined, but the amount of sugar found in the portal vessels or lac teals 

 does not at all correspond with the amount that disappears from the 

 cavity of the intestines.' 



"Foster saj^s, 'This suggests the possibility of the sugar of the 

 intestinal contents undergoing the butyric acid fermentation (during 

 which, as is well known, carbonic anhydride and hydrogen are evolved), 

 and thus, so to speak, put on its way to become fat. More- 



over, it is probable that by other fermentative changes a considerable 

 quantity of sugar is converted into lactic acid, since this acid is found 

 in increasing quantities as the food descends the intestines.' 



"No doubt the lactic acid is con verted into butyric acid, which, in turn, 

 is converted into soluble soaps, and which may perform, and we believe 

 do perform, important offices. As will be seen further on, fat is often 

 covered with soap, when absorbed, and soaps are found in the chyle, as 

 well as some fatty acids. Furthermore, it is shown that fats undergo 

 still further emulsion after being absorbed while passing through the 

 lacteals to enter the general circulation. Now, these soaps may be, and 

 very likely are, the chief agents in accomplishing this. One of the 

 arguments always advanced by the advocates of artificial butter is that 

 it possesses better keeping qualities and does not become rancid, and is, 

 therefore, more wholesome than rancid butter. Now, it is true that 

 it does not set free butyric acid (as it contains no butyrine), which gives 

 the rancidity to butter, but, as it contains some cellular tissue (in our 

 specimens considerable), it undergoes a different decomposition, which 

 is liable to develop the septic material peculiar to dead animal matter, 

 and which is often very poisonous to human beings. On the other 



