1166 PHYSIOLOGY 



substances dissolved in fatty vehicles. Thus the administration of mercury 

 is often carried out by the inunction of mercurial ointments, and the fact that 

 mercurial salivation may be produced in these conditions shows that a certain 

 amount of the mercury must have been absorbed. It is difficult to imagine 

 that any appreciable amount of cod liver oil will be available for the nutrition 

 of the infant when this substance is administered by rubbing it on the skin. 

 On the other hand, the moist mucous surfaces, such as the conjunctiva or 

 the mucous membrane of the respiratory passages, as well as raw surfaces of 

 the skin, e.g. which have been deprived of their epidermal layer by the 

 application of blisters, permit of the rapid passage of substances in watery 

 or oily solution. 



