Note 195 — PHARMACOLOGIA. ON THE OPERATIONS OF MEDICINAL BODIES, AND ON THE CLASSIFICATIONS FOUNDED ON THEM. (continued 2)

This fact derives its pathological interest from the probability that, in certain states of disease, the Lithic acid assumes this peculiar modification, giving to the sediments of urine those beautiful hues which were formerly considered by Proust, as the effect of an acid, which he named the Rosacic; now as the Purpuric acid, or rather the Purpurate of Ammonia, says Dr. Prout, is nothing more than Lithic acid modified by the action of Nitric acid, and as I have already shewn that the Pink and Lateritious sediments occasionally contain nitric acid in some peculiar state of combination, the nature and origin of the colouring matter cease to be problematical.