290 DISEASES CLASS III. 1. 1. 10. 



it, arises from excess of volition, and not from a suspension of it; 

 and though, like other kinds of epilepsy, it often attacks the pa- 

 tients in their sleep, yet those two, whom I saw, were more fre- 

 quently seized with it while awake, the sleep-walking being a 

 part of the reverie. See Sect. XIX. and XXXIV. 3. and Class 



II. 1. 7. 4. and III. I. 2. 18. 



M. M. Opium in large doses before the expected paroxysm* 

 10. Asthma convulsivum. The fits of convulsive asthma return 

 at periods, and are attended with cold extremities, and so far 

 resemble the access of an intermittent fever; but, as the lungs 

 are not sensible to the pain of cold, a shivering does not suc- 

 ceed, but instead of it violent efforts of respiration; which have 

 no tendency, as in the humoral asthma, to dislodge any offend- 

 ing material, but only to relieve the pain by exertion, like the 

 shuddering in the beginning of ague fits, as explained Class 



III. 1. 1.2. 



The insensibility of the lungs to cold is observable on going 

 into frosty air from a warm room; the hands and face become 

 painfully cold, but no such sensation is excited in the lungs; 

 which is another argument in favour of the existence of a peculiar 

 set of nerves for the purpose of perceiving the universal fluid 

 matter of heat, in which all things are immersed. See Sect. 

 XIV. 6. Yet are the lungs nevertheless very sensible to the de- 

 ficiency of oxygen in the atmosphere, as all people experience, 

 when they go into a room crowded with company and candles, 

 and complain, that it is so close, they can scarcely breathe; and 

 the same in some hot days in summer. 



There are two diseases, which bear the name of asthma. The 

 first is the torpor or inability of the minute vessels of the lungs, 

 consisting of the terminations of the pulmonary and bronchial 

 arteries and veins, and their attendant lymphatics; in this cir- 

 cumstance it resembles the difficulty of breathing, which attends 

 cold bathing. If this continues long, a congestion of fluid in 

 the air-cells succeeds, as the absorbent actions cease completely 

 before the secerning ones; as explained in Class I. I. 2, 3. 

 And the coldness, which attends the inaction of these vessels, 

 prevents the usual quantity of exhalation. Some fits cease be- 

 fore this congestion takes place, and in them no violent sweat- 

 ing nor any expuition of phlegm occurs. This is the humoral 

 asthma, described in Class II. I. 1.7. 



The second kind of asthma consists in the convulsive actions 

 in consequence of the disagreeable sensations thus induced; 

 which in some fits of asthma are very great, as appears in the 

 violent efforts to raise the ribs, and to depress the diaphragm, 

 by lifting the shoulders. These, so long as they contribute t0 



