366 NITPJTE OF AMYL IN THE COLLAPSE OF CHOLERA. 



and the thick blood which distended it is emptied out, no more 

 will How. From the blood, which in health acts as the diffuser 

 of heat to the extremities, and the equaliser of temperature in 

 the body, being thus pent up in its interior, and no longer 

 circulating through the skin or lungs, and becoming itself cooled 

 as it warms them, the surface and the expired air both become 

 cold, while a thermometer in the rectum may show a tem- 

 perature higher than any observed even in the most intense 

 fever.* 



All the symptoms are thus easily and satisfactorily explained 

 by the hypothesis of Parkes aud Johnson, that the circulation 

 is obstructed in the lungs ; and even cases which at first sight 

 might seem to militate against it, on closer examination serve, 

 I think, only to confirm it. Such cases are those observed by 

 Mackinnon,t where, after a check had been put to the vomiting 

 and purghig, the voice, breathing, and warmth of the skin 

 became natural ; the face had none of the peculiar character of 

 the disease; the patients walked about and called for food, 

 saying that they felt well ; but their pulse was imperceptible, 

 and in one or two days they died of coma. In these cases, it is 

 true, the imperceptible nature of the pulse might be partly due 

 to feeble action of the heart ; but it seems not improbable that 

 it was owing in great measure to persistent obstruction in the 

 pulmonary circulation. It would appear almost impossible for 

 men to live in such a condition ; but Sir James Paget has shownf 

 that persons may have their pulmonary circulation obstructed 

 to an enormous extent, and yet hardly present a symptom of 

 anything wrong, so long as the systemic vessels contract in 

 unison with the pulmonary ones, and do not allow any more 

 blood to pass through them in a given time than is able to flow 

 through tlie obstructed arteries in the lungs during a similar 

 period. 



While the hypothesis of obstruction to the pulmonary circu- 

 lation readily explains the symptoms in collapse, it is not easy 

 to ascertain how this obstruction is occasioned, and several 



* Griiterbock, Virch. Arch,,, vol. xxxviii, p. 30. 

 t Reynolds' System of Medicine, vol. i, p. 163. 

 X Medico- Chirurgical Transactions, 1845, p. 359. 



