ANALYSIS OF 1000 PARTS OF BLOOD.

ANALYSIS OF 1000 PARTS OF SERUM.

Specific gravity of the blood 1060.000 Specific gravity of serum 1028.000

Water

.

Notwithstanding the results of these laborious investigations, we must acknowledge that the establishment of an absolute standard, expressing the constitution of the blood in health, is impracticable, if not impossible. In the first place, we must not only establish a formula for each class and species of animal, and for the human race generally, but we must establish a formula for each temperament, and for each race and nation, under every conceivable circumstance of soil, climate, and occupation.

Another important field of investigation is the changes of the constituents of the blood during thirst and starvation.

In almost all the forms and grades of fevers the patients are deprived of food, either by the physician or by the condition of the digestive apparatus. Accompanying this condition we have rapid chemical changes, and often perverted nutrition. The constituents of the blood may be divided into two great classes, the nutritive and force elements. From the chemical changes of these two classes arises a third class, called the excrementitious. Now, both classes of matter, the force elements and the nutritive elements, are consumed, chemically altered, and converted into excrementitious offending compounds during starvation. In like manner both classes are converted into excrementitious compounds in fever. Now, to determine definitely what changes are due to fever, we must first determine what are due to starvation; that is, to the consumption of the blood during nutrition, and the generation of the forces by which the machinery is worked. This can only be accomplished by determining the changes of the blood during starvation, and the forces and products resulting from these chemical changes. A standard will thus be established, to which the changes in fever may be referred. In fever we have a pathological state (abnormal changes) superadded to those normally existing. We can never have accurate pathological knowledge until we determine the physiological changes. Another difficulty meets us:

The elements of the blood are liable to variations, not only of quality, but also of quantity. We must determine, not merely the relative variations, but also the quantitative. By analyzing the phenomena carefully, and attributing to each its just position, we may eliminate the elements of the problem only to a probable issue, we may determine the character of the changes and of the morbific agent; but the absolute amount of these changes will be unknown, without some method of determining the amount of blood in the system. Here, then, is a great and serious difficulty in the establishment of an absolute standard of comparison. We have no accurate means of determining the amount of blood circulating through the system. It is evident that obscurity on this point introduces obscurity everywhere, and impairs the value of every standard we may erect. The truth of this proposition is established by looking at the great discrepancies which have prevailed among physiologists, with regard to the amount of blood contained in the bodies of warm-blooded animals. Blumenbach estimated the quantity in an adult man at 8.5 to 11 pounds, Reil at 44, Haller computed it at 28 to 30, Borelli 20, Young 40, Dumas 25, Fletcher 30, Ancell 30. M. Valentin, by his method of injecting water, arrived at the following results. The numbers represent the relation existing between the quantity of blood and the weight of the body

Large dogs (the mean of four experiments), as .
A lean, debilitated sheep, as

Cats, female (the mean of two experiments), as
A large female rabbit, as

1:4.5

1: 5.02

1:5.78

1: 6.20

From these data he estimates the amount of human blood to be

This would give in a man weighing 150 lbs. 30 lbs. of blood, and in a female weighing 130 lbs. 26 lbs. Lehman determined the amount of blood in the bodies of two criminals, who were decapitated, to be from 17.5 to nearly 19 lbs., or one-eighth the weight of their bodies. My own observations have established the fact, that the amount of blood varies with the different classes of animals, and corresponds with the rapidity of the chemical changes of the blood and tissues, and with the physical, vital, and nervous forces. These investigations have established that the blood is more abundant in warm than in cold-blooded animals. These facts are important in their bearing upon the phenomena of health and disease.

When we have a large supply of blood, and a rapid distribution of blood, then we will have a rapid generation of force.

In the present state of science we possess no method of determining absolutely the amount of blood existing in the animal body. Whilst we might determine the amount of blood contained in the large blood vessels, it would be utterly impossible to determine the amount in the capillaries, because the quantity lost after fatal hemorrhage is no criterion whatever, and the latter portions drawn are also mixed with the fluids of the organs and tissues. Our knowledge on this subject is vague, and may be summed up in a few sentences. The young are said to have more blood than adults and the aged, and lean persons are said to have more blood than very fat persons. As in certain diseases there is a rapid destruction and perversion of the elements of the blood, and as it appears that these chemical changes are destined to fulfil certain salutary offices, as the destruction of peculiar poisons, it is evident that an increase or diminution of the blood, even within the limits of health, must modify not only the course of diseases, but also the action of remedial agents. The determination of an absolute standard is farther impossible, because in the present state of science the methods of analysis are not strictly accurate. We have no absolutely accurate method of determining the colored bloodcorpuscles.

We have stated these difficulties, not with the design of casting doubt and discredit upon physiological and pathological science, but rather with the design of pointing out the great complexity of the phenomena, and defining the bounds of knowledge, and inducing caution both in investigation and in the generalization of the results of observation and experiment.

CHAPTER IV.

CHANGES OF THE BLOOD IN MALARIAL FEVER.

Color of the blood and serum in malarial fever and other diseases-Specific gravity and coagulation of the blood in malarial fever and other diseases-Fibrin decreases in malarial fever-Formation of heart-clots in congestive fever during life-Cause of the coagulation of the blood unknown-Chemical changes of the blood in malarial fever compared with the changes of the blood in other diseases -Blood-corpuscles are destroyed during malarial fever, and during the slow action of the poison, unattended with fever-Principles of treatment founded upon these changes-Time when these changes of the blood commence.

Ir is important that we should in the first place determine the extent and bearing of our means of investigation, and of our know. ledge.

In the present state of physiological and pathological science, and methods of investigation, our knowledge of the changes of the blood during disease is limited to an examination of the venous blood of the extremities, or of the surface of the trunk. We have no means of investigating the changes of the blood in different organs and tissues during the different stages of disease.

The changes of the blood in the different organs can only be determined by an examination of the blood remaining in those organs after death. The information yielded by an examination of the blood of the extremities and surface of the trunk during life, and of the blood remaining in the organs after death, must be imperfect, because we can only superficially determine the composition of the blood at different stages of the disease, and are wholly unable to determine its changes in different organs and tissues, and apparatus, and are limited to an examination of the blood in the organs only after a fatal termination, and must, therefore, remain without the facts which would enable us to determine definitely the various steps of the chemical changes, and the physical, chemical, physiological, and toxicological action of the resulting compounds. The examination of the blood after death must always yield imperfect and unsatisfactory information, even with reference to the effects of the morbific agents upon the blood, immediately

preceding death, because in the hours of death, when the circulation. and respiration are impeded, and the temperature diminished, and the nervous and vital influences enfeebled, many physical and chemical changes of the blood may result from the disturbances of the circulation and respiration, and from the alterations of the process of endosmose, and from the chemical changes of the organs. and tissues through which the blood passes, entirely independent of the actions of the morbific agents.

In an examination of this kind it would be necessary first to establish a standard formula of the constitution of the blood in each organ, and tissue, and apparatus, by an examination of the blood after death, in the organs, and tissues, and apparatuses of those who had died in perfect health, and also during starvation. In the preceding chapter we demonstrated that the constitution of the blood varied with each animal, and in the human race varied with temperament, age, previous habits, diet, occupation, and previous diseases and race; and hence concluded that it was difficult if not impossible, to establish a universal typical formula of venous blood. It is evident, therefore, that the difficulties of establishing typical formulæ of the constitution of the blood in the various organs, and tissues, and apparatuses, would be increased a thousand fold.

Besides these difficulties, the poison or poisons which produce the changes of the blood in malarial fever have never been isolated, and we know nothing whatever concerning its physical, chemical, physiological, and pathological relations with the elements of the blood, and nervous system, and organs, and tissues by direct experiment. We can only infer them from the changes going on during the progress of the disease. So complicated are the phenomena, and so imperfect our knowledge of malarial fever, that we are unable to answer such important questions as these: Does the poison act by catalysis, by its mere presence in the blood, inducing a series of chemical changes, which result in the alteration and destruction of the elements of the blood? or does it undergo chemical changes itself, and during these chemical changes generate from its own elements, and from those of the blood, substances capable of preventing and arresting the secretions of the organs, and of interfering with the nutrition and chemical actions of the muscular and nervous systems, and causing aberrated muscular and nervous actions? Are the acceleration and disturbance of the circulation and respiration, and the aberration of the nervous and muscular phenomena, due to VOL. XII.-20