Dale and Richards studied the effect of histamine on the control of the circulation and showed its peripheral action to be located in the capillaries and smaller arterioles.

Richards made many experiments concerning the secretion of urine. Among other things he collected and analysed the fluid from a single glomerulus; his work confirmed the theories of Ludwig and Cushny.

Experimental proof that the initial step in urine production is the formation in Bowman’s space of a protein-free ultrafiltrate of plasma and that reabsorption of certain substances must occur in the tubules since they were present in the filtrate but absent from the final urine. One of the most significant of all publications in renal physiology.