USES OF THE SINUSES OF THE NOSE. 457 



appearance of the fibres, while they are distinguishable, that they are finally 

 arranged with great delicacy. It is certain that the impressions from whence 

 we derive the perceptions of many odors, must be very slight, as some 

 odorous bodies will impregnate the air of a large chamber for a great length 

 of time, without losing any sensible weight. 



With respect to delicacy of structure and sensibility, it is probable that the nose 

 holds a middle rank between the eye or ear, and the tongue : and on this 

 account the mucus is necessary as a covering and defence of its surface. 



It has been ascertained, by the investigations of chemists, that this mucus con- 

 tains the same ingredients as the tears already described, namely, animal 

 mucus and water ; and muriate of soda, and soda uncombined j phosphate of 

 lime, and phosphate of soda. 



The animal mucus, which is a most important ingredient in the composition, 

 resembles the mucilage formed by some of the vegetable gums in several 

 particulars ; and differs from them in others. 



The mucus of the nose, if it remain there long after it is secreted, becomes 

 much more viscid in consistence, and changes from a whitish color to one 

 which partakes more or less of the yellow. It is probable that an incipient 

 putrefaction may occasion these changes in it. 



The use of the frontal, maxillary and other sinuses, communicating with the 

 nose, has been the subject of some inquiry. As there can be no stream of 

 air through them, and as the membrane lining them is neither so thick, villous 

 nor flexible as that lining the nose, it may be concluded, a priori, that they 

 are not concerned in the function of smelling. This opinion is strengthened 

 by the fact, that very young children, in whom these sinuses scarcely exist, 

 enjoy the sense of smelling in perfection. The following fact is also in sup- 

 port of it. The celebrated Desault attended a patient, in whom one of the 

 frontal sinuses was laid open by the destruction of the bone which covered it 

 anteriorly. This patient was able to breathe a short time through the sinus 

 when the mouth and nose were closed : at the request of Desault he breathed 

 in this manner when a cup of some aromatic liquor was held near the open- 

 ing of the sinus, and had not the least perception of odor. This experiment 

 was repeated several times. 



Many physiologists believe that these sinuses have an effect in modulating the 



39 



