tion, of the respiration, or of the functions of the brain, give rise to it; it is not unfrequently met with during the puerperal state, especially at the accession of puerperal fever.

The volume of the pulse may be greater than usual, when it is said to be full, as in general plethora, and in the early stages of acute diseases; or less than usual, when it is known as small or contracted-being sometimes so small that it is said to be thread-like-as in anæmia, after severe hemorrhage, and in all cases of great prostration. When the pulse resists compression it is termed hard, firm, or resistent; when very hard and at the same time small, wiry; softness of the pulse is almost synonymous with compressibility, and generally indicates defective tone and loss of vital power.

In fever, a dicrotous pulse-that is to say, a pulse which beats twice as fast as in health-which is at the same time hard, is a very unfavorable symptom, especially if it continue more than twenty-four hours; if, however, it is succeeded by epistaxis, and then disappears, it is more favorable. When, in fever, a hard dicrotous pulse lasts for many days, without any tendency to hemorrhage, the case-in nine out of tenends fatally. In hæmoptysis, long-continued epistaxis, and internal inflammations, a very hard dicrotous pulse sometimes occurs, which resists all treatment, and portends a fatal issue; no matter how much the other symptoms may improve, so long as the pulse retains this character, the patient is in imminent danger.'

Lastly, if the pulse at both wrists be not isochronous or equal-if the beats do not occur at the same time-we must suspect disease of one or the other radial arteries, or that pressure is made upon some part of the arterial tract between the heart and wrist by a tumor, aneurism, &c.

Condition of the Capillaries.-The state of the capillary circulation on various parts of the surface, often furnishes indications of some importance as respects vascular action and vital power, especially in the exanthematous fevers and in cachectic diseases. By pressing the finger upon the skin and noticing the rapidity with which the blood returns into the whitened spot, we ascertain the rapidity of the circulation through the capillaries; when the blood returns quickly into these minute vessels, the circulation is active and healthy; when it returns immediately, and the skin is of a vivid color, there is congestion; while if the redness at any one part remains unaffected by pressure, we may be sure that there is extravasation of blood. As old age advances the capillaries Graves, op. cit. p. 50.

become impaired in vital tone, and the skin consequently is rendered colder and paler than in adult life. The same occurs frequently from exhausting diseases, denoting a failure in the general strength of the system which demands our greatest attention.

Venous Symptoms.-The veins furnish signs of disease by their dilatation and over-distension, as occurs in the veins of the temples, face, and neck, in congestion of the brain; by the slowness or rapidity of their distension when pressure is applied in their course to the heart, showing the excess or deficiency of blood in the system; and by their occasional pulsations. The occurrence of a venous pulse results either from a continuation of the heart's impulse through the capillaries, when the circulation is much excited; or from an artery lying under or near a vein; or it may be due-when felt in the jugulars-to a retrograde current, produced by inordinate contraction of the right ventricle and regurgitation of blood, owing to hypertrophy of the right ventricle with dilatation of the right auriculo-ventricular orifice and imperfect closure of the tricuspid valve.

State of the Blood.-In man, as well as in the most perfect animals, the blood during life never rests, but is constantly in active motion, running in a double circle, from the first respiration until death. Having become impure in the course of its circulation, it is purified in the lungs; the pure blood is then sent all over the body, when a part of it becomes solid, a part is removed by the secreting organs, and the rest becoming venous is again returned to the lungs and heart.

The supply of blood being adapted to the capacity of the vascular system, any deviation from the normal quantity will affect the whole body. Excessive fulness of blood will give rise, in proportion to the fulness, to a full, broad, and tense pulse; to congestion of the sinuses and other vessels of the cerebro-spinal system; to congestion of the lungs, liver, and other important viscera, as well as to spontaneous hemor rhages. When the blood is deficient in quantity, the pulse will be found soft, weak, and very compressible, the impulse of each wave of fluid through the artery being quick and sudden: the vital powers will be found depressed to a low state, the organic nervous energy weakened, and the different functions will be feebly, if not imperfectly performed.

The morbid effects of the loss of blood may be divided into the immediate and the remote. The immediate effects are syncope or fainting, from its slightest to its fatal form; convulsions, most apt to occur in children, and in cases of slow

and excessive draining of blood; delirium, as is frequently seen in flooding after parturition; coma, the comatose condition being often as perfect as after a fit of apoplexy; and, lastly, sudden dissolution may take place from copious bloodletting. The remote effects are exhaustion with excessive reaction; exhaustion with defective reaction; exhaustion with sinking of all the vital powers; mania; and coma, from which it is impossible to recover the patient.

Dr. Marshall Hall has suggested, that, in cases in which it is doubtful whether the pain or other local affection be the effect of inflammation or of irritation, the doubt should be solved by placing the patient upright, and bleeding to incipient syncope; in inflammation much blood flows, in irritation very little. As this has been considered a very important means of diagnosis, it is necessary for the reader to be acquainted with it, though I doubt very much the propriety or even the necessity of resorting to such a test. Happily, owing to our increased knowledge of disease, the use of the microscope, and the aid of chemistry, we are able, in the present day, to ascertain all that it is desirable to know of the nature of the blood from the examination of a very small quantity, such as a few drachms, or even less.

If the quantity of blood in the system influences disease, it will readily be imagined that the quality of this fluid must do so to a very important extent; and such is the case. There is, however, no standard analysis of blood to which all other analyses may be positively referred, since each moment the composition of this fluid, as a whole, is changing. Thus, the water is always varying in amount; the nitrogenized and unnitrogenized substances are always changing in quantity; even the salts, even the alkalescence of the blood is in a perpetual state of variation, being hardly the same at any two moments of the day. If this is the case in health, how much more so will it be the case in disease. That the constituents of the blood undergo various and important alterations in their amount, in different constitutional affections, will be readily seen by the table on p. 117, which presents roughly the most striking variations.'

The facts which have been satisfactorily made out concerning the morbid conditions of the human blood are not very numerous, and much remains to be accomplished. Amongst the chief diseases, however, in which a pathognomonic condition of this fluid has been discovered, I may mention inflammatory affections, characterized by the constant increase in the amount

See Lecture on Animal Chemistry, by Dr. Bence Jones, Lancet, 20th January, 1850.

of the fibrin; anæmia, by a decrease in the red corpuscles; certain renal affections, by the diminution of the solids of the serum, and frequently by an accumulation of urea; gout, by the existence of uric acid, as has been so ably demonstrated by Dr. Garrod; diabetes, by the presence of sugar; jaundice, by the existence of the coloring principle of the bile; insanity -more than two-thirds of the cases of madness being the result of some alteration in the blood-(Romberg); and cholera, in which there is a diminution of the water-causing the blood to become thicker, tar-like, and less coagulable, an increase in the solid portions of the serum-especially the albumen, and a retention of urea.

A few years since Dr. Garrod discovered a substance in the blood which crystallizes in microscopic, octahedral crystals, and which he regards as oxalate of lime.' And, more recently, a very curious disease has been described by Virchow and Dr. Hughes Bennett, named by the latter leucocythemia, from Auxes, white, xuros, a cell, and ae, the blood; literally, whitecell blood. On examining the blood microscopically, under a magnifying power of 250 diameters, in a case of leucocythemia, the yellow and colorless corpuscles are at first seen rolling together, the excess in the number of the latter being at once recognizable, and becoming more evident as the colored bodies became aggregated together in rolls, leaving clear spaces between them filled with the colorless globules. A drop of blood taken from a prick in the finger is sufficient for examination. The chief symptoms presented by a person suffering from leucocythemia are great pallor, with gradually increasing emaciation and debility. It will probably be found, as we learn more of this affection, to be associated with enlargement of some or all of the following glands-the liver, spleen, thyroid, thymus, supra-renal capsules, and lymphatics.

'Medico-Chirurgical Transactions, 1849.

For an account of the chemical and microscopical examination of the blood, see Chapter XI, Section 1.

SECTION 5. SYMPTOMS CONNECTED WITH THE URINARY AND SEXUAL ORGANS.

The symptoms furnished by the urinary organs divide themselves into two classes, i. e., into those to be gathered from a chemical and microscopical examination of the urine, for the purpose of discovering those morbid conditions of this secretion which may be produced by local disease of the renal organs, by various constitutional conditions, and by disease of the brain or spinal cord; and those which depend on the modes of voiding this secretion. The former will be fully considered in Chapter XI, Section 4; the latter will now be treated of

The Excretion of the Urine may be difficult, or painful, or changed, or arrested. With respect to the difficulty of voiding the urine, three grades have been distinguished: dysuriaJus, with difficulty, and cupov, the urine-in which the urine is voided with trouble or effort, pain, and a sensation of heat in some part of the urethra; strangury-pay, to squeeze, and oupe-in which the difficulty is extreme, the urine issuing drop by drop, and being accompanied by heat, pain, and tenesmus at the neck of the bladder; and ischuria—1x, I arrest, and oupov-in which no urine at all can be passed.

The first two species-dysuria and strangury-should always attract attention, since they cause great suffering, and lead to conditions by no means devoid of risk, more particularly in aged persons. They may proceed-either from disease of the urinary organs or passages, as, stricture, or inflammation of the urethra; hypertrophy of the middle lobe of the prostate; spasm, catarrh, inflammation, or ulceration of the bladder; and fungous or polypoid growth;-from morbid states of the urine, as, the admixture of pus, blood, mucus, gravel, &c.; or from this secretion being too irritating; or from the existence of one or more calculi in the bladder or urinary passages or from disease of the adjoining viscera, as in instances of dysentery, disease of the liver or spleen, tumors of the abdomen, and uterine or ovarian affections.

Ischuria in which no urine at all can be passed-is divided into that of suppression, and that of retention. Suppression of urine-sometimes called ischuria renalis, in which no urine is secreted-is a most dangerous symptom, since the injurious, effete, and poisonous materials which should be excreted by