1884.] NATURAL SCIENCES OF nilLADELPUIA. 281 



ON THE BEHAVIOR OF PETROLATUM IN THE DIGESTIVE TBACT. 



BY N. A. RANDOLPH, M. D. 



The mixture of hydrocarbons, recognized by tiie pharmacist 

 under the name of petrolatum, and popularly used under the 

 commercial names of cosmoline or vaseline, presents on super- 

 ficial inspection few points of difference from some of the organic 

 fats of the same consistency. Close examination reveals differ- 

 ences, both in physical properties and in chemical constitution, 

 between the bodies just compared. One point of difference, which 

 I have as yet been unable to find recorded, lies in the respective 

 behavior of these two groups, when in contact with the absorbent 

 surfaces of the digestive tract. Thus, while the organic fats, as 

 ordinarily taken in food, are readil}' and almost completely ab- 

 sorl)ed,this soft paraffin is entirely rejected, and found unchanged 

 in tlie feces. 



During eight days, I took daily one-half ounce of commercial 

 viiseline, in addition to m^^ regular diet. Digestion was in no 

 wise altered, and no appreciable results ensued. Later, two 

 healthy adults each received, in the course of forty -eight hours, 

 one ounce of vaseline. Their alvine dejections for three days from 

 the beginning of this observation were collected and dried, and, 

 at the suggestion of Dr. John Marshall, of the University of 

 Pennsylvania, extracted with petroleum ether. Making a slight 

 allowance for incompleteness in extraction, the vaseline ingested 

 was, in each case, recovered in its totality, showing that it had 

 passed through the economy unchanged and unabsorbed. 



There are some important medical applications of these facts, 

 the discussion of which would be out of place here, and which I 

 reserve for further experiment ; but the following deductions ap- 

 pear permissible, and are of strictly biological interest. 



I. Pure petrolatum, while entirely unirritating to the digestive 

 tract, is valueless as a food-stuff*. 



II. The results of the experiments here described lend support 

 to the theory that oleaginous matters are dependent, for their 

 absorption, not upon mechanical, but upon vital activities, and 

 that in such absorption the selective power of the protoplasm of 

 the intestinal epithelium is manifested. 



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