Coagulation

“ A mercurial Water made of Sublimate and Aqua Calcis, made a very considerable whitish Coagulation, and rendred it all a thick Jelly, which being held over the Fire, turned to a Curd and a Serum. A Solution of Roman Vitriol produced a Coagulation likewise; so did Allum dissolved in Water, but it made a greater Alteration in some than it did in others, though the Mucilages were taken from subjects of the same Species. Saccharum Saturni did inspissate it, which appeared to be a true Coagulation, because with the Fire they would turn to a distinct Coagulum and Serum. ”

“ Probably not, for most of the body fluids are of that colloidal nature in which coagulation occurs in the presence of small quantities of special agents. Such a result might cause the individual to lose his equilibrium. ”

“ Although complete coagulation does not occur suddenly as the quantity of electrolyte is increased, yet the interval between the concentration at which, in a given time, the turbidity becomes visibly greater and that at which the particles have become large enough to settle out or to be retained by a filter is usually so small that a fairly definite concentration can be specified at which each electrolyte causes a certain, experimentally determinable, degree of coagulation in a definite time. ”

“ Crystalloid substances are also to be divided into two classes with respect to their effect in coagulating colloids. Non-electrolytes, whether organic or inorganic, have no tendency to produce coagulation; indeed, we have seen that organic substances, like ether, glycerine or sugar, often increase the stability of the suspension. On the other hand, strong electrolytes, that is, substances which are themselves largely dissociated into electrically charged particles or ions, cause coagulation, when their concentration in the solution becomes sufficiently great. ”

“ All natural proteins, when in colloidal solution, may be coagulated, forming a semi-solid gel, which cannot again be rendered soluble except by decomposition. The most familiar example of this type of coagulation is that of egg-albumin, when eggs are cooked. This coagulation may be produced by heat, by the action of certain enzymes, or by the addition of alcohol to the solution. (3) All solutions of plant proteins are optically active, rotating the plane of polarized light to the left, in every case. ”

“ The cells in all parts of the body require water and this is supplied to them from the blood. Water is present in the corpuscles as well as in the plasma and forms about 80 per cent of the entire volume of the blood.
Coagulation of the Blood.—If the blood is exposed to some unnatural condition, such as occurs when it escapes from the blood vessels, it undergoes a peculiar change known as coagulation.11 In this change the corpuscles are collected into a solid mass, known as the clot, thereby separating from a liquid called the serum. ”

“ The coagulation of the blood, while it is a matter of fundamental importance in physiology, has peculiar interest for the surgeon, on account of the special feature of coagulability of inflammatory exudations and the part played by lymph in the healing of wounds and various other pathological phenomena, such as the sealing of divided arteries by blood-clot. ”

“ Nor can it be affirmed with perfect confidence, that all forms of protoplasm are liable to undergo that peculiar coagulation at a temperature of 40°-50° centigrade, which has been called "heat-stiffening," though Kühne's beautiful researches have proved this occurrence to take place in so many and such diverse living beings, that it is hardly rash to expect that the law holds good for all. ”

“ Weigert lays stress upon the existence of a coagulation of the protoplasm of the cells, with an early disappearance of the nuclei, as the essential feature of this form of necrosis, the conditions present being regarded as analogous to those met with in the coagulation of the blood. The term coagulative necrosis has consequently been introduced by Cohnheim to represent the process first fully described in detail by Weigert. ”

“ In the intravascular coagulation experiments above described, all the rabbits were carefully weighed, and the amount of nucleo-proteid injected until coagulation occurred was measured. This would give for albinoes and pigmented individuals the amount per kilogramme of body-weight required to kill in each case, and would afford a measurement of the relative resistance of the two races. It was found that the resistance of albinoes towards the coagulative effects of injected nucleo-proteids was to that of pigmented individuals as 1·5 to 1·0. ”

“ Fill three tumblers each two thirds full of water and set them in a warm place. Pour into one of the tumblers, and thoroughly mix with the water, two tablespoonfuls of the blood containing the Epsom salts. After an interval of half an hour add blood to the second tumbler in the [pg 038] same manner, and after another half hour add blood to the third. The water dilutes the salts so that coagulation is no longer prevented. Jar the vessel occasionally as coagulation proceeds; and if the clot is slow in forming, add a trace of some salt of calcium (calcium chloride) . ”

“ There was no difference between the behavior of old and fresh specimens.
(3) No acceleration of coagulation in vitro was observed even with the highest concentrations tried, namely 25 and 50 per cent.
(4) Irrigations made with fresh dry coagulen in solution and sterile solution in ampoules on superficial bleeding from the foot-pads of 3 normal and peptonized dogs and local application to hemorrhages from dissected femoral arteries and bone and liver wounds of 3 dogs showed that coagulen was no more active than normal saline. ”

“ In many cases of this sort it is no easy matter to stop the bleeding by ligaturing a bleeding vessel; sometimes it is impossible. Nevertheless, transfusion should not be withheld owing to a risk of increased hæmorrhage supposed to follow a rise in blood pressure. Usually the patient is debilitated by prolonged suppuration, and often his blood is deficient in its power of coagulation. It has been found that a transfusion, in addition to replacing some of the blood that has been lost, tends to improve the patient’s resistance to micro-organisms, and to shorten the coagulation time of the blood. ”

“ Various Salts.—Of experimental interest only it may be recorded that coagulation has been effected by means of various chemical “salts“—e.g., calcium chloride, barium chloride, magnesium chloride, sodium chloride, aluminium sulphate, magnesium sulphate, sodium sulphate, etc. None of these has been found to have any practical application, except, perhaps, calcium chloride, which is used in small quantity as an accelerating agent in a special process of anaerobic coagulation, which will receive mention in the following chapter. ”

“ Thus, upon mixing suspensions of colloidal gold and of arsenious sulphide, no coagulation occurs, but when the suspensions of ferric hydroxide and arsenious sulphide, which we have seen from their behavior on migration have opposite electric charges, are poured together, there is immediate coagulation, and in a few minutes the precipitate settles, leaving the liquid clear above. ”

“ Fuller estimates the amount of sulphate of alumina required for the clarification of the Ohio River at Louisville at 3.00 grains per gallon of water filtered if all applied at one point, or at 1.75 grains by taking advantage of subsidence to its economical limit prior to the final coagulation. The saving to be effected in this way is sufficient to justify the works necessary to allow it to be carried out. With less turbid waters, or waters highly turbid for only short intervals, the advantages of double coagulation would be less apparent. ”

“ The area of coagulation necrosis becomes filled with white blood cells, and the dry necrosed part is liquefied by the cocci. Suppuration in dense structures causes considerable masses of tissue to die and to be cast off, and these masses float in the pus.
An abscess heals by the collapse of its walls, and the formation of an abundance of granulation tissue; in many cases granulations of one wall join those of the other side, the entire mass of granulations being converted into fibrous tissue, and this tissue contracting, heals by third intention. ”

“ The Coagulum of the Mucilage made with an Acid, and the Infusion of the Peruvian Bark and several other Astringents, I kept and dried, which when they were first put to the Teeth, seemed a little gritty, though after they were moist they were of a softer Nature. All the Mixtures made of the Mucilage with an Acid and an Austere, produced not only a plentiful Coagulation of a white Colour, but such a one as was of a thicker Consistence, and not Soluble in fair Water, as that was which was made with an Acid only. ”

“ Occasionally a distinct acceleration in the clotting, compared with the normal, may be observed. Wright has further ascertained in his excellent researches, that the clotting time can be influenced by drugs: calcium chloride, carbonic acid raise, citric acid, alcohol and increased respiration diminish the clotting power of the blood.
Recently Hayem has repeatedly called attention to a condition, that is probably closely connected with the coagulability of the blood. Although coagulation has set in, the separation of the serum from the clot occurs only very slightly or not at all. ”

“ If therefore a Medium be not used, it so happens, as ’tis wont to be in any Earth that is too moist, and therefore not [capable of] bearing fruit. So that nothing is more necessary than to have a due regard of mediocrity, not onely in the Solution, but in the Coagulation likewise.
And this is that way by which the Solution done in the Air, and the Coagulation made in the Sun, doe reduce the Mercurial water, and the Minerals prepared with Salt into fusile and tinging Stones; which thing the Common fire will never perform in a glass closed up, and without the Air. ”

“ It is necessary that the precipitate should be sufficient, and that it should be formed practically all at one time. The amount of coagulant necessary to accomplish this purpose is dependent upon the turbidity of the raw water. With practically clear waters sulphate of alumina of the ordinary commercial strength, that is to say, with about 17 per cent soluble oxide of aluminum, used in quantities as small as 0.3 or 0.4 of a grain per gallon, will produce coagulation. As the turbidity increases larger amounts must be employed. ”

“ Adhesiveness of corpuscles and coagulation are both brought about by the operation of noxious agents upon the tissues of the part concerned. But it by no means follows that they are in all respects analogous phenomena. We have seen that normal blood has no innate tendency to coagulate, and needs no action of the tissues upon it to ensure its fluidity. But the blood-corpuscles may he naturally adhesive bodies, possessing a viscosity only kept in abeyance by some influence exerted upon them by the living tissues in their vicinity: and such appears to he really the case. ”

“ The agency of the first of these preventive powers need not be further noticed. The second is extensively employed for embalming purposes, and in the preparation of bodies for anatomical studies, by baths, or injections into the arteries of solutions of corrosive sublimate, acetate of alumina, sulphate of iron, tannin, wood vinegar, and creasote; this last body, however, does not appear to act by direct combination, but by the complete (catalytic) coagulation it produces in all the tissues of the body that have protein for their base. ”

“ However this may be, it is pretty certain that the blood generally remains fluid in the human body after death from chloroform, only because it usually remains fluid in every kind of sudden death. When a patient dies slowly of illness, the body cools gradually before death takes place, and ammonia keeps exhaling in the breath, if Dr. Richardson is correct, whilst the formation of this alkali must be almost suspended. In many cases, we know that coagulation of the blood commences before the respiration and circulation have ceased. ”

“ To remove the effusion during the inflammatory stage does not appear to be rational treatment unless the quantity is so excessive as to endanger the life of the patient. The fluid remains limpid unless exposed to air or contact with foreign substance. When, after a time, there is some coagulation, it is only of a thin layer which covers and protects the roughened surface of the pleura. A certain amount of effusion is useful; it separates and bathes in a bland fluid the tender and inflamed surfaces, and keeps at rest the affected portion of the lung. ”

“ The efficiency of mechanical filters depends entirely upon the use of coagulants. Without coagulants they can only be used to remove very large particles. The efficiency of the filtration depends much more upon the kind, and amount, and method of application of coagulant than upon the arrangement of the filter. In fact, the arrangements of the filter are more directed to the convenience and economy of operation and washing than towards the efficiency of the results.
The conditions which control the efficiency of mechanical filters have been discussed in connection with coagulation. ”

“ When coagulation has taken place, then an earthy humour is excreted and is drawn around, and the earthy portion drying up, the membranes are produced both as matter of necessity, and also for a certain purpose. ”

“ Apprehending that the fixed air in the distilled water occasioned the coagulation, or separation of the oily part of the soap, only by destroying the causticity of the lixivium, and thereby rendering the union less perfect betwixt that and the tallow, and not by the presence of any acid; I impregnated a fresh quantity of the same distilled water with fixed air, which had passed through half a yard of a wide barometer-tube filled with salt of tartar ”