If the partially inflated lungs of dogs sensitized to horse serum are perfused with Locke's solution containing from 0.25 to 2 per cent, of horse serum, the following anapylactic phenomena are noted:1 (a) A 75 per cent. reduction in the rate of perfusion flow. (b) Complete immobilization of the lungs, the lungs showing no tendency to collapse when the tracheal clamp is released. (c) Marked perivascular edema. (d) The escape of large amounts of perfusion fluid from the trachea. The tracheal flow usually begins during the fourth minute, and reaches a maximum by the seventh minute. With medium sized dogs, about 1,000 c.c. of perfusion fluid escapes from the trachea by the end of the seventh minute.
To determine the nature of the anaphylactically increased capillary permeability thus demonstrated, various substances have been added to the perfusion fluid, and quantitative determinations of these substances made in the fluid recovered