every ten pounds of healthy human blood consist of an almost clear liquid spoken of as the serous part, or serum, the remaining pound and a half being an infinite number of very minute bodies, partly colourless and partly red, and individually so small that their existence in the liquid is only discovered when very powerful microscopes are employed in the observation. The colourless serum, and the microscopically granular or corpuscular constituent, are properly the dead, and the living, portions of the blood. flow out from the warm vessels of the liv ing body into cooler air. It separates into a clear thin liquid, which does then consist of pure albumen and saline principles mingled with water, and into a clot composed of a dense, fibrous, sticky substance, which is albumen pushed one step farther towards the living condition. The albu men, thus rendered coagulable and capable of solidifying into a fibrous clot without the aid of a high temperature, is not chemically changed in any appreciable way from that which still remains liquid in the thin serous residue. The chemist is not able to discover any intrinsic atomic or molecular difference between the two; and the physiologist, in his turn, is able to say nothing more about the matter than this - that the albuminous principle derived from the food, without any appreciable or tion, without the addition or subtraction of any material ingredient, has, in the blood-stream of the living body, been made more plastic and organizable, more adhesive and ready to be converted into fibre, and membrane, and texture. The serous liquid is simply the perfected extract of the digested food rendered mobile and fluid by the addition of a very large proportion of water. Of the eight pounds and a half which have been spoken of, no less than eight pounds are water, and could be distilled off as water alone. The remaining half-pound, which gives discoverable change of material composi serosity to the water, is indeed almost entirely albumen derived from the food-a complex substance all but identical with the white of eggs, and capable like it of being coagulated by heat. Thus constituted it is the great pabulum or plastic base out of which the organized substance It is a notable fact that a singularly of the living body is constructed. In the small quantity of this fibrinous principle egg of the oviparous animal the deposit is sufficient to make the blood thick and of albumen is arranged round the gerini-adhesive enough for all practical purposes. nal yolk to be ready there when the first work of fabrication is entered upon in building up the chicken. In the blood the albumen is provided for exactly the same purpose it is food in the ultimate state of preparedness for conversion into textures of the widest range of diversity. The water of the serum is merely the vehicle furnished to keep the albumen moveable and thin, and in that way ready for its proper office ready to be poured along the system of pipes laid down for its conveyance through all, and to all, parts of the frame, and to be in that way thrown into close and intimate relation with all the films, fibres, and textures that have to be continually refreshed and renewed by its plastic agency. But the serous liquid of living blood is viscid from the presence of something yet more tenacious and plastic than albumen. The serum of the blood coagulates of its own accord when the blood is caused to In the fifteeen pounds of blood that are contained in the body of a man of ordinary stature there is not more than half an ounce of adhesive fibrin at any one time. But it must be understood that the fibrin which is there is being continually expended in practical service, and at the same time as continually formed anew out of the relatively large store of albumen contained in the serum. The fully matured fibrinous principle is absolutely essential for the plastic work which is involved in organization. But too large an amount of it at any one time in the channels of the circulation would be of neces sity fatal to the orderly accomplishment of the process. A very slight increase over the ordinary allowance of standard health would render the entire mass of the blood so thick and unruly in its adhesiveness, that it would be ever prone to stagnate in the minute channels and pas sages it has to perineate. This is abuud antly shown in certain disorders of the in-, reckoning that of this blood one-seventh flammatory and rheumatic class, where the part, or two pounds and two ounces, is derangement is primarily due to the too made up of corpuscles, and that there are rapid and abundant conversion of albumen seventy thousand millions of corpuscles into fibrin. In the arrangements which in each cubic inch of the two pounds and are incident to the condition of perfect health an ample reserve of albuminous material is kept constantly in store, and fresh portions of this reserve are worked up into the more elaborate and quasi-vital condition of adhesive fibrin exactly as this is needed for the construction of the more fibrous textures of the frame. two ounces, the sum total for the whole array of corpuscles comes out nearly two and a half millions of millions. It is to be feared that the only notion that can be realized from this computation is the very inadequate and crude one, that the minuteness and number of these most wonderful little objects are far beyond all clear apprehension. Thus much of the nature of the blood is made out by very simple observation, un- The individual corpuscles of the blood aided by any of the more refined instru- are just visible, as exquisitely minute rings, ments of philosophical research. But the when looked at through a good microscopother, and living, portion of the blood can ic object-glass of one inch focus, which only be studied by the skilful employ-magnifies forty diameters. With an ment of very powerful microscopes. When eighth of an inch object-glass, used with a minute droplet of freshly drawn blood an eye-power that qualifies it for magnifyis placed on a slip of glass, and is there ing 1,200 diameters, each corpuscle appressed out into a thin film and then pears as if nearly half an inch wide. The highly magnified, it is at once seen that most expert histologists now accomplish a countless myriad of minute, round bodies even more than this, and successfully emare floating about in the liquid, the great- ploy in their examination microscopic er proportion of them being of a yellowish-powers that magnify even 2.800 diameters. red hue, and therefore very conspicuous When the circulating blood is observed in the clear serum, from the effect of con- in the small vessels of the web of the frog's trast, but a smaller proportion of them foot, it is seen that the coloured corpuscles being almost without colour. These, in are hurried on in a thickly serried phalanx default of any better name, are called the in the clear stream which flows through "little bodies," or "corpuscles," of the the channel of each little vessel, with a blood. Various attempts have been made tendency to crowd themselves up into the to give some clear idea of the surpassingly middle of the passage as much as they minute dimensions of these blood-corpus- can. The colourless corpuscles are obcles. But it must be confessed that both served for the most part loitering along in observation and description are alike inad- the outskirts of the stream, often in actual equate to do so. It does not accomplish contact with the sides of the vessel, and very much to say, as is often done, that on that account advancing in the current ten millions of them could lie tessellated with less resolute and impetuous pace. together as a pavement upon the surface Under ordinary circumstances there are of a square inch, and that from twenty-five but few colourless corpuscles in comparito thirty-two hundred of them could be son with the coloured ones-not more ranked in single file within the linear ex- than a single one to every two or three tent of an inch. Perhaps not very much hundred. To cursory observation the more is effected when the further state- colourless corpuscle looks like a translument is added that, in a single human cent ball, knobbed over by bosslike probody, there are six thousand times as jections, and rolling over and over as it many of these microscopic blood-corpus- moves. More exact and careful scrutiny, cles as there are living human creatures however, shows that the little sphere is inhabiting the world. Allowing fifteen incessantly changing its form-protruding pounds of blood for the quantity contained now one part and now another of its outer in the body of a man of fair stature, and surface, and twisting and contorting itself every ten pounds of healthy human blood consist of an almost clear liquid spoken of as the serous part, or serum, the remaining pound and a half being an infinite number of very minute bodies, partly colourless and partly red, and individually so small that their existence in the liquid is only discovered when very powerful microscopes are employed in the observation. The colourless serum, and the microscopically granular or corpuscular constituent, are properly the dead, and the living, portions of the blood. flow out from the warm vessels of the liv ing body into cooler air. It separates into a clear thin liquid, which does then consist of pure albumen and saline priaciples mingled with water, and into a clot composed of a dense, fibrous, sticky substance, which is albumen pushed one step farther towards the living condition. The albumen, thus rendered coagulable and capable of solidifying into a fibrous clot without the aid of a high temperature, is not chemically changed in any appreciable way from that which still remains liquid in the thin serous residue. The chemist is not able to discover any intrinsic atomic or molecular difference between the two; and the physiologist, in his turn, is able to say nothing more about the matter than this that the albuminous principle derived from the food, without any appreciable or discoverable change of material composition, without the addition or subtraction of any material ingredient, has, in the blood-stream of the living body, been made more plastic and organizable, more adhesive and ready to be converted into fibre, and membrane, and texture. The serous liquid is simply the perfected extract of the digested food rendered mobile and fluid by the addition of a very large proportion of water. Of the eight pounds and a half which have been spoken of, no less than eight pounds are water, and could be distilled off as water alone. The remaining half-pound, which gives serosity to the water, is indeed almost entirely albumen derived from the food-a complex substance all but identical with the white of eggs, and capable like it of being coagulated by heat. Thus constituted it is the great pabulum or plastic base out of which the organized substance It is a notable fact that a singularly of the living body is constructed. In the small quantity of this fibrinous principle egg of the oviparous animal the deposit is sufficient to make the blood thick and of albumen is arranged round the gerini-adhesive enough for all practical purposes. nal yolk to be ready there when the first work of fabrication is entered upon in building up the chicken. In the blood the albumen is provided for exactly the same purpose it is food in the ultimate state of preparedness for conversion into textures of the widest range of diversity. The water of the serum is merely the vehicle furnished to keep the albumen moveable and thin, and in that way ready for its proper office ready to be poured along the system of pipes laid down for its conveyance through all, and to all, parts of the frame, and to be in that way thrown into close and intimate relation with all the films, fibres, and textures that have to be continually refreshed and renewed by its plastic agency. But the serous liquid of living blood is viscid from the presence of something yet more tenacious and plastic than albumen. The serum of the blood coagulates of its own accord when the blood is caused to In the fifteeen pounds of blood that are contained in the body of a man of ordinary stature there is not more than half an ounce of adhesive fibrin at any one time. But it must be understood that the fibrin which is there is being continually expended in practical service, and at the same time as continually formed anew out of the relatively large store of albumen contained in the serum. The fully matured fibrinous principle is absolutely essential for the plastic work which is involved in organization. But too large an amount of it at any one time in the channels of the circulation would be of neces sity fatal to the orderly accomplishinent of the process. A very slight increase over the ordinary allowance of standard health would render the entire mass of the blood so thick and unruly in its adhesiveness, that it would be ever prone to stagnate in the minute channels and pas sages it has to permeate. This is abuud antly shown in certain disorders of the in-, reckoning that of this blood one-seventh flammatory and rheumatic class, where the part, or two pounds and two ounces, is derangement is primarily due to the too made up of corpuscles, and that there are rapid and abundant conversion of albumen seventy thousand millions of corpuscles into fibrin. In the arrangements which in each cubic inch of the two pounds and are incident to the condition of perfect two ounces, the sum total for the whole health an ample reserve of albuminous array of corpuscles comes out nearly two material is kept constantly in store, and and a half millions of millions. It is to be fresh portions of this reserve are worked feared that the only notion that can be reup into the more elaborate and quasi-vital alized from this computation is the very condition of adhesive fibrin exactly as this inadequate and crude one, that the minis needed for the construction of the more uteness and number of these most wonderfibrous textures of the frame. ful little objects are far beyond all clear apprehension. The individual corpuscles of the blood are just visible, as exquisitely minute rings, when looked at through a good microscopic object-glass of one inch focus, which magnifies forty diameters. With an eighth of an inch object-glass, used with an eye-power that qualifies it for magnifying 1,200 diameters, each corpuscle appears as if nearly half an inch wide. The most expert histologists now accomplish even more than this, and successfully employ in their examination microscopic Thus much of the nature of the blood is made out by very simple observation, unaided by any of the more refined instruments of philosophical research. But the other, and living, portion of the blood can only be studied by the skilful employment of very powerful microscopes. When a minute droplet of freshly drawn blood is placed on a slip of glass, and is there pressed out into a thin film and then highly magnified, it is at once seen that a countless myriad of minute, round bodies are floating about in the liquid, the greater proportion of them being of a yellowish-powers that magnify even 2,800 diameters. red hue, and therefore very conspicuous When the circulating blood is observed in the clear serum, from the effect of con- in the small vessels of the web of the frog's trast, but a smaller proportion of them foot, it is seen that the coloured corpuscles being almost without colour. These, in are hurried on in a thickly serried phalanx default of any better name, are called the in the clear stream which flows through "little bodies," or "corpuscles," of the the channel of each little vessel, with a blood. Various attempts have been made tendency to crowd themselves up into the to give some clear idea of the surpassingly middle of the passage as much as they minute dimensions of these blood-corpus- can. The colourless corpuscles are obcles. But it must be confessed that both served for the most part loitering along in observation and description are alike inad- the outskirts of the stream, often in actual equate to do so. It does not accomplish contact with the sides of the vessel, and very much to say, as is often done, that on that account advancing in the current ten millions of them could lie tessellated with less resolute and impetuous pace. together as a pavement upon the surface Under ordinary circumstances there are of a square inch, and that from twenty-five but few colourless corpuscles in comparito thirty-two hundred of them could be son with the coloured ones-not more ranked in single file within the linear ex- than a single one to every two or three tent of an inch. Perhaps not very much hundred. To cursory observation the more is effected when the further state- colourless corpuscle looks like a translument is added that, in a single human cent ball, knobbed over by bosslike probody, there are six thousand times as jections, and rolling over and over as it many of these microscopic blood-corpus- moves. More exact and careful scrutiny, cles as there are living human creatures however, shows that the little sphere is inhabiting the world. Allowing fifteen incessantly changing its form-protruding pounds of blood for the quantity contained now one part and now another of its outer in the body of a man of fair stature, and surface, and twisting and contorting itself A third distinctive mark of the living state is that the substance of the life-endowed corpuscle has the power of constructing a peculiarly complex material which is no longer alive, although it has been so directly produced by living operation, and which furthermore is quite unproducible in any other way. This is what is known technically as "formed substance." There is not unreasonable ground for the notion which is entertained by some physiologists, that the highly plastic fibrin of the blood is itself "formed substance" of this character, which has been made by the elaboratin; energy of the corpuscles. into all sorts of indescribable shapes. The There is no shadow of doubt that the pale corpuscle of the blood is formed out of the fully prepared and most finished albuminous material; that it is, so to speak, the consummation of the first act of vital organization. It is, in fact, a living crea ture fashioned, in some way or other, out of the richly elaborated material of the liquid in which it appears. In the colourless corpuscle life is contemplated in its most rudimentary condition; it is life seen at its dawn. By these various observations and considerations physiologists arrive at the conclusion that there are three altogether distinct states of complex material with which they have to deal in considering the first steps of vital organization : — 1st. that which is known as food-substance, or formative material. 2nd. living substance dowed with absolute vitality. And, 3rd. formed substance, the final result of vital operation, not itself alive, but which has been formed by the process of living elaboration, and which can only be formed in that way. Formative material and living substance are seen respectively in the albuminous principle and in the corpuscles of the blood. More particular allusion will have to be made presently to the formed material. In the meantime it should be understood that the most intelligent modern physiologists seem to be pretty well satisfied that it is a fundamental law of living economy that "formative The most striking, and, on the whole, material" must pass through the ordeal of most characteristic peculiarity of this re- becoming itself living substance" before markable body, which distinguishes it from it can by any possibility be "formed subthe unvitalized plastic matter that lies stance;" and that this virtually is the reaaround, and that has been so immediately son why the "formed substance" of orand so intimately concerned in its forma- ganized structures cannot be produced by tion the great stamp, as it were, of the any unliving agency. Hence, also, all the new-born vitality with which the constitu- three distinct states of organic material ent material has become endowed is its are of necessity present in living bodies. marvellous inherent power of spontaneous For some time the actual living substance motion. The constituent spherules and of an organized structure was spoken of molecules of which its mass is built up are, as its "protoplasm," or first organized not firmly compacted together, but inces- base. The more expressive and more philsantly dancing hither and thither, and roll-osophic term, " Bioplasm" (Life Plasm, or ing over and over among themselves. Living Plasm), has now been accepted, in its stead. A second stamp-mark of the vital condition, which for the first time appears in the colourless corpuscle, is individual enlargement, or growth. The living corpuscle increases its own substance out of the molecular contributions which it receives from the surrounding nutrient material. Exquisitely and almost inconceivably small as these living corpuscles of the blood are found to be, in comparison with the grosser objects that form the unmicroscopic " sphere of ordinary observation, they are nevertheless, it must be remem 1 |