Dr. Maxwell, of Calcutta, uses the following language: "The development of the stages of fever entirely depends on the changes the _leaven has effected_. If this change has been such that the blood has become too thick to flow through the lungs, then, as a matter of course, the collapse stage is developed in excess; in other words, _cholera asphyxia_ is exhibited. The blood, unable to pass through the middle passage into the arteries, collects and swells out the veins, giving that deadly or blue color to the skin. When the vomiting and spasms come on, this mass of blood in the veins is squeezed with great force, and hence the clammy moisture that is forced from every part during these fits. There is no pulse, because there is no blood in the arteries." "There are also lethargy and languor, and oppression in breathing, caused by the blood being collected in the veins. These make up the principal links in the chain of mechanical symptoms." Dr. Bell, dwelling on this congestive character of the blood, and endeavoring to point out the best mode of relief, observes, "When this has reached to such a point as to oppress the action of the heart, yawning first and then shivering, or a sense of suffocation and pain in the precordia, are the indications of oppressed circulation, and of the commencing effort of the heart to overcome the mass of blood which is stifling it. If, by the application of tourniquets to the limbs, or by _bleeding_, part of the blood which is rushing from the extremities to increase this congestion is prevented from reaching the great veins, the heart, excited to increased action, is enabled, by this relief, more quickly to overcome the obstruction and restore the balance of the circulation, and the paroxysm passes off. If not thus mechanically aided, the heart, after a severe struggle to maintain the circulation during the period of constriction, is at length relieved by this nervous disturbance or spasm of the capillary circulation passing off of itself, and then the heart and arteries, so long excited by the struggle, maintain for a time their increased action after the obstruction in the capillaries is removed, and produce apparent febrile action. Presently this excitement subsides, the vessels become relaxed, and sweat succeeds. The vessels continue in this state for a longer or shorter period, according to circumstances, till they at length recover their ordinary tone and action in the intermission. This fever, however, is not fever properly so called, but reaction; and the sweating not critical, or essential, but relaxation. The cold stage is alone essential, and is the physiological cause of the subsequent stages."