246 THE EFFECTS OF USE AND DISUSE. sooner, however, do they become fixed in a convenient place than they lose their microscopic oars, lose, one after another, their special senses, become thus reduced to shapeless, inert, masses of protoplasm, and thus vegetate simply for the rest of their existence. Such reduction and waste occurs as the result of disuse throughout the animal scale. We realise thus the force of Schiller's observation to Körner; "Die Hauptsache ist der Fleisz; denn dieser giebt nicht nur die Mittel des Lebens, sondern er giebt ihm auch seinen alleinigen Werth." (The chief thing is industry; it not only furnishes the means of living, but also gives to life its sole worth). The atrophic changes in the nervous tissue incident to age, make themselves manifest in the action of the nerve centres as well as in the loss of conductivity in the nerve fibres. The intellectual and moral faculties suffer the same alterations as the special senses. The organs of communication with the external world being blunted in their nice perceptions, the old man has only his memories whence to derive his intellectual food. As he cannot comprehend the world about him in its new order, he looks upon all that is new with distrust, if not absolute aversion. But this blunting of the sympathies enables age to regard events and occurrences dispassionately, and hence peculiar wisdom is ascribed to this period of life by all peoples and in all lands. "If we consider this epoch," remarks Carl Vogt, one of the most profound philosophers of his day, "in its retrocessions. of the feelings, in its insensibility to external impressions, in its lack of the loftier inspirations, in its insipidity of intellectual productions, we may well cease to begrudge it, the wisdom usually ascribed to it." At last, ensues the last stage of atrophy, and : "From Marlborough's eyes the tears of dotage flow THE BLOOD AND ITS PROPERTIES. 247 LECTURE XII. THE BLOOD AND ITS PROPERTIES. CONTENTS. The Value of the Blood-The Transfusion of Blood-The Constitution of the Blood-The Color of the Blood-Reaction of the Blood -The Odor of the Blood-The Taste of the Blood-The Temperature of the Blood-The Weight of the Blood-The Quantity of the Blood -The Morphology of the Blood-The Red Blood Corpuscles-Size of the Red Corpuscles-Number of the Red Corpuscles-Elasticity of the Red Corpuscle-Constitution of the Red Corpuscles-Use of the Red Corpuscles-The Colorless Blood Corpuscles-The Blood Plasma-The Coagulation of the Blood-The Blood as the Substitute of the Body. The Value of the Blood. The blood is for the most part, the prepared, digested, fluidified, food. But the blood is made up also of the waste products of the body. The blood thus officiates as the fresh food (solid, liquid, and gaseous) supply and at the same time, as the sewage escape. No where in art may we observe a nutrient supply conveyed along the same conduits or tubes with waste matter without suffering contamination. "The blood circulating through the body may be regarded as a river flowing by numerous canals through a populous city, which not only supplies the wants of the inhabitants, but conveys from them, all the impurities which through various channels find their way into its stream" (Bennet). The mass of the blood is the digested food. To secure the elaboration of the coarse elements of the food into the finished elements of the blood, is the work of a digestive apparatus, which is extensive and complicated according to the nature of the food. For food is of no use to the body 248 THE TRANSFUSION OF BLOOD. until it is converted into blood. It is the blood which is consumed in the processes of life; thus directly or indirectly, all animals are carnivorous. The blood of plants is the sap which is made up of the fluidified salts of the earth. The material which acts as blood for the lowest forms of animal life is the sea or the water in which they live. Blood (Saxon, blod), in some form or other, is thus the most important juice in the body, and its value was recognised long before its nature and character were established. We observe something of the popular recognition of its significance in the aversion, or feeling of horror, which the mere sight of it occasions. The shedding of blood is associated with the loss of life. So blood is the fluid, so to speak, with which tragic artists paint. Helena, when she finds Lysander asleep (Midsummer Nights Dream), can not believe him hurt, because as she says: "I see no blood, no wound!" And the watchman in the grave yard scene (Romeo and Juliet) appreciates the injury to life with the exclamation and injunction: "The ground is bloody; search about the church yard: The Transfusion of Blood. Perhaps no single experiment so convincingly exhibits the fact that "the blood is the life" as the practice of injecting fresh healthy blood into the veins of an animal dying from its loss. Almost simultaneously with the reception of the blood, the respiration becomes more profound, the pulse becomes again perceptible, consciousness returns with motion and sensation, in short, the animal is restored to life. THE TRANSFUSION OF BLOOD. 249 The operation of transfusion of blood was first practised on man by a French physician, Denis, June 15, 1667, with defibrinated blood from a calf, though numerous experiments had been previously made upon lower animals. The first recorded intimation of the operation is found in Ovid's Metamorphoses, book vii, fable ii, in the order of Medea to the daughters of Pelos: "unsheath your swords, and exhaust the ancient gore, that I may replenish his empty veins with youthful blood." But this statement is usually construed by commentators to have only metaphorical meaning, and to have reference to the vivifying effect of a potent decoction which Medea had previously used on animals and men. However this may be, it is known that the modern operation of transfusion was largely discussed by the metaphysicians of the middle ages, that period so replete with curious and fantastic projects, and was even practised to some extent upon lower animals. As a sample of the fabulous expectations entertained of transfusion, at this time, I may mention that it was generally believed that the long sought secret of rejuvenation had been at last discovered. Very soon after the first practice of the operation upon man, marvelous results began to be reported. Cases of insanity were cured, lost special senses were restored, and aged and decrepit constitutions rehabilitated with the vigor of youth. Time, the experimentum crucis of all discoveries, soon dissipated all these conceits, and the number of accidents and fatal results which attended the operation at last brought it into disrepute, when legal injunction caused the practice of it to be suspended and forgotten. In this oblivion it laid, then, until the beginning of our own century, when it was revived by a distinguished obstetrician of Dublin, Blundell (1818), with such improvements in method and restriction in practice, as to give it permanent place among the most valuable acquisitions to modern therapy. 250 THE TRANSFUSION OF BLOOD. In our day, transfusion is limited to cases of hemorrhage, where it is peculiarly adapted to meet the indications, and to cases of poisoning by toxic agents (sewer gases, for instance) for which we have no antidote. A temporary renewal or protraction of life may also be effected with it in cases of phthisis, and sometimes permanent relief afforded in cases of inanition from any cause, when the ordinary avenues of food are temporarily blocked, or may not be addressed, as in cases of gastric ulcer. It is highly probable, however, that other nutrient fluids, an artificial serum, or milk, will gradually substitute blood in the majority of cases. Though the transfusion of a few ounces of blood usually suffice, according to the observations of J. Worm Müller, rabbits and dogs may receive as much as eighty per cent. additional blood without permanent injury. Inexplicable laws regulate the kind of blood which an animal may receive. The transfusion of the blood of birds into the veins of mammals produces convulsions and death, as does also the transfusion of some mammals blood into the veins of other mammals. Dogs blood may be injected into the veins of rabbits with perfect impunity, while sheeps blood rapidly proves fatal (Mittler). Most remarkable results have been obtained by the injection of blood into the veins of animals recently dead. BrownSéquard has performed a great many experiments of this kind, and his accounts of effects secured would seem incredible, were they not in full accord with our knowledge of the part the blood plays in the animal economy. On one occasion, he decapitated a dog, taking care to make the section below the point where the vertebral arteries penetrate their osseous canals. "Ten minutes after cessation of the respiratory movements of the nares, lips and lower jaw, I inserted into the three arteries of the head canulæ con |