Why do we lose the sense of smell when we have a cold?

    The sense of smell depends upon scented things in the air reaching the lining of our nose, especially certain small parts of the lining of  the nose. 

When we have a cold, this lining, or mucous membrane, of the nose gets swollen, and produces a muth greater amount of mucus than usual, as we all can tell by the number of handkerchiefs we have to use in a day. The chief reason why we cannal smell so well when we have a cold is, that this mucus,  constantly  pouring out of thelining of the nose and running over it, prevents the scent of things getting to the sensitive part of the nose, and washes away any solid scented  particles that there may be in the air. Also, it may very likely be that the poisons produced by the microbes that cause a cold, poison the living cells of the mucous membrane, and also poison the tiny ends of the nerves of smell that run to it, so  that even if scented air does reach the sensitive part of the mucous membrane, they cannot be felt.    This applies alike to scenls coming in from outside and also to the scents of food, which pass up at the back of the roof of the mouth inta the nose, and which, if we have not got a cold, help to give our food half its flavour.