564 REMEDIES IX BRONCHITIS AND PHTHISIS. 



greater when they are taken in a mucilaginous vehicle, which, 

 adhering to the irritated mucous membrane over which it 

 passes, keeps the sedatives in contact with it for a longer time, 

 and thus allows them to exert a more powerful action. But the 

 sedatives which we give to relieve cough are not unfrequently 

 administered in the form of solution, and then, though their 

 local action must be comparatively slight, they still lessen a 

 troublesome cough. Their action here is a different one from 

 that which we have just discussed, but it is possessed by the 

 sedative whether given in the form of linctus or of solution. 

 In either way it is swallowed by the patient, absorbed from the 

 stomach and intestines into the circulation, and carried by the 

 blood to the medulla oblongata, and also to the inflamed mucous 

 membranes, in which the blood circulates freely, just as well as 

 in other parts of the body, although here its action is likely to 

 be very much less than if it were applied for a length of time 

 directly, as in the shape of the linctus; but, as we have 

 mentioned, the linctus can only be applied to the back of the 

 tongue and throat, and the source of irritation of the afferent 

 nerves may be in the bronchi or in the lung itself. Here, no 

 doubt, a liuctus cannot penetrate, but we may to a certain 

 extent act locally upon the nerves by the use of spray and 

 inhalation. Some of these, such as the vapour of conium and 

 the vapour of hydrocyanic acid, are intended to lessen the 

 irritability of the sensory nerves in the respiratory passages, and 

 thus lessen cough. Others, such as the spray of ipe acuanha, 

 and inhalation of essential oils and terebinthinous substances, 

 have probably a different action, and do not lessen the irrita- 

 bility of the sensory nerves in the respiratory passages, but 

 alter the nutrition of the mucous membrane in such a w^ay as 

 to diminish the irritation w^iich the abnormal condition of the 

 membrane exerts upon the nerves. When the irritation is 

 situated in the larynx, as in cases of laryngeal phthisis, one of 

 the best means of relieving it is by applying the sedatives 

 locally, whether by means of a brush, or, what is perhaps still 

 better, by blowing it, in the form of a powder, directly upon 

 the irritated surface. A useful application in laryngeal phthisis 

 consists of a mixture of morphia and starch, in the proportion 



