THIS BLOOD.] 



CHEMISTRY. 



331 



.1 



just as sulphur or phosphorus is in tho albuminous 

 substances. Its presence is indispensable for the for- 

 mation of tho colouring matter ; therefore is iron so 

 efficacious in many diseases, when the blood contained 

 in the finest vessels, and shining through the skin, has 

 lost its colouring matter. This red pigment of the 

 blood, when fresh, is soluble in water, and is still more 

 so in alkalies, which are even capable of dissolving it in 

 a dry state. The alkali in the blood facilitates, there- 

 fore, tho solution of the colouring matter. 



No albuminous substance is so abundantly dissolved 

 in the blood as pure albumen, which, remaining in the 

 liquor after its separation from the clot, coagulates ouly 

 at the boiling-point, just like the white of an egg. 

 Traces of caseine are found with the albumen in the 

 blood. 



Fresh blood manifests an alkaline action with litmus. 

 This is to be attributed to the presence of a basic phos- 

 phate of soda. Amongst the salts of the blood, phos- 

 phate of soda and bicarbonate of soda predominate. 

 To these salts may be added the compound of potash. 

 with the same acids : besides tho sulphates of soda and 

 potash, the phosphates of lime, magnesia, and oxide of 

 iron, are all conveyed to the blood with the chyle. 



Iii our own times chemists have succeeded in detecting 

 fluoride of calcium among tho constituents of the blood. ! 



Just as of all other albuminous matters existing in the 

 serum of tho blood, albumen, strictly so called, is the 

 most abundantly represented ; so also common salt, or 

 chloride of sodium, predominates among the inorganic 

 substances. Chloride of potassium is present in relatively 

 smaller quantity. 



Blood contains, if examined when taken quite fresh 

 from the living body, oleino anil margarine. But they 

 arc very rapidly decomposed into olcic and margarie 

 soaps, by the influence of the albuminous substances ami 

 the carbonates of potash and soda iu the blood. With 

 them another fatty substance is also present, remarkable 

 for the amount of nitrogen and phosphorus which it con- 

 tains ; and a second, distinguished from most vegetable 

 and animal fats by its phosphorus. 



Analogous to the neutral fats, consisting only of oxy- 

 gen, hydrogen, and carbon, we find a compound inter- 

 mediate between fat and wax, containing less oxygen 

 than the former, and incapable of being saponified, 

 bearing the name of bile-fat, only because it had first 

 been discovered in the bile. 



Sugar is always found, only in a small quantity, in the 

 blood. Before it reaches the circulation, it has been for 

 the greatest part transformed into fat. 



In order to give an idea of tho proportionate quantity 

 of the constituents of the blood, in round numbers, we 

 add tho following summary review. A thousand parts of 

 blood contain 



Fibrine 2 



Blood globules . .131 



Albumen ..... 71 

 Compound of clilorine and salts . 5 



Fat 2 



Water 789 



Total 1000 



ORIOIX OF THE SOLID SUBSTANCES or THE HITMAX 

 BODY. 10. The blood is conveyed from tho heart to 

 all parts of the body. The heart propels it, by regular 

 contractions, Into the vessels, which have also a regular 

 pulsation, and are called arteries. These ramify in 

 smaller and smaller vessels, which at length, from their 

 minute size, are called capillaries, and pervade in very 

 great number all the organs of our frame. By means of 

 the arteries, every part of the body receives arterial 

 blood. 



The dissolved substances of the blood pass everywhere 

 through the walls of the capillaries, fonning thus what 

 is called the juice of nutrition. As the fluid from which 

 crystals are precipitated is called mother-lye, so we may 

 call this juice of nutrition mother-juice of the solid con- 

 stituents of the body ; for all vesicles or cellules, fibres, 

 and formless deposits, composing tho several solid parts 



liquefied state, flow over the interior -walls of the intes- 

 tines. The chyle of a person fasting is more watery and 

 thin than thai of one who has had a plentif id meal. 



Up to the formation of the knots just mentioned, 

 the lacteals commonly contain an alkaline solution of 

 compounds of clilorine and salts, among which common 

 salt and phosphate of soda predominate, with a certain 

 quantity of sugar; also, if any amylaceous substances 

 have been present in the food, neutral fats, as well as 

 oleic and margaric soaps that is to say, compounds of 

 | oleic and margaric acid with soda and potash; and, 

 lastly, albumen and fibrine. 



The last-named substance is not yei quite identical 

 with the proper fibrine of the blood, of which the cha- 

 racteristic property is that of spontaneously coagulating 

 without the application of heat or acid when withdrawn 

 from the living body. The fibrine of the chyle, which 

 has in other respects the same properties, acquires this 

 quality only on its way from the intestinal canal to the 

 blood-vessels, and after haviug left that part of the 

 lacteals which is convoluted into knots. 



In the lacteals also begins the development of a red 

 colouring matter, which, besides nitrogen, carbon, hy- 

 . and oxygen, contains some iron. The quantity 

 of the lattur is as constant as it is small in proportion 

 to that of the four first-named elements. This sub- 

 must necessarily be formed from one of the 

 ions principles, and an iron salt of the chyle. 

 -10 occasion of the light-red colour BO often re- 

 '. in the superior part of the thoracic duct. This 

 'nt of the chyle, containing iron and nitrogen, 

 / matter of the blood, because blood pos- 

 sesses no other constituent of this colour. 



Iluw far the formation of blood has now advanced, 

 will best be seen if we pass to the description of tho 

 blood itself. 



9. The Blood. In the blood of man, vesicles are 

 suspended containing a red substance, and white, gra- 

 nulated corpuscles. The former are called coloured, tho 

 latter nni-oloured blood globules. 



The fluid, in which the blood globules are continually 

 in motion in the living body, is always impregnated 

 with three difitrent kinds of gaa oxygen, carbonic 

 acid, and nitrogen. Apart from these gases, the blood 

 consists of a solution of salts, albuminous substances, 

 fat, and sugar. When withdrawn from the veins or 

 arteries, the blood deposits a red dot, leaving a yellowish 

 liquid. The former contains principally the fibrine and 

 1 matter of tho blood; the latter is albumen and 

 salts. Fat is equally distributed in both. This 

 tion into clot and liquid arises from tho property of 

 fibrine to coagulate, as soon as the blood is removed 

 from the influence of tho living body. While coagu- 

 lating, the fibriue incloses tho blood globules, and there- 

 fore the clot retains the red colour. In the vessels of 

 the lining body, tibriue always exists in the dissolved 

 state. This is in part effected by tho salt and tho 

 predominance of alkali in the blood ; but only in part, 

 because the salts and alkalies are not able to keep the 

 fibrine in asolublo stateout of the body. The supposi- 

 tion may, therefore, be justified, that the fibrine leaves 

 the blood and blood-vessels of the living body before it 

 has become ripe for coagulation. Out of the body, 

 fibrino undergoes this development in tho blood itself, 

 ^ulates, even where temperature, motion, and 

 . Hi from tho external air have been maintained, 

 artificially, as much as possible as it had been during 

 life. Wo consider tho oxygen contained in the blood 



to be the chief cause of this change. 

 The coloured globules consist of a white capsule, con- 

 taining a red liquid : this capsule being of an albu- 



, is so transparent that it lx 



entirely invisible when the colouring matter has been 



washed out of the globules by a sufficient quantity of 



water. The red colouring matter, which is contained in 



tho blood globules, besides several salts, fat, and allm- 



ii,'h its pellucid enclosure. I r. >n M 



at which, in the colouring m;ittor of tho blood, 



'i ted with nitroge.,1, carbon, hydrogen, and oxygen, 



