Excerpt from First Principles of MedicineThe color of the blood is caused by red particles diffused through a transparent ¿uid which is called serum (whey), from its resemblance to that ¿uid when blood is first drawn the red particles may be seen ¿oating about by the means of a microscope, but when it stands they settle down to the bottom and form a cake or clot (called cruor or crassamentum).Some capillaries are too small to admit the red particles unless when they are enlarged by in¿ammation, as in the eye, which when in¿amed changes from white to red, besides that, even the red capillaries are so minute that they are not visible Individually to the naked eye till enlarged by in¿ammation.About the PublisherForgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.comThis book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully, any imperfections that remain are intentionally left to preserve the state of such historical works.