(It 



BLOOD. 



BLOOD. 



61J 



plant*, and seems to bo the chemical compound with which the active 

 function* of life are connected. 



The second constituent of the Clot, the red matter, being hoarier 

 than the fibrin, gradually subsides to the lower surface, where it in 

 always found forming the bottom of the clot The proportion of this 

 rod matter to the fibrin differs in different classes of animals, and even 

 in the same animal at different times. The greater the energy and 

 activity of the animal the larger is the proportion of the red matter, 

 and it is also generally large in proportion to the elevation of the 

 animal temperature. 



When a drop of blood is placed under the microscope it is found to 

 consist of the liquor sangumis and a number of globules or cells. It 

 is these latter which constitute the red matter of the blood. When 

 carefully examined these cells are found to be of two kinds the one 

 white or colourless, the other red. The former except in states of 

 diimunn are far less in number than the latter, and ore found to be 

 identical with cells which are found in the lymph and chyle. Hence 

 they are sometimes called lymph- or chyle-corpuscles. These white 

 corpuscles have only of late yours attracted much attention, though 

 they had been described as far bock as the time of Hewson. In man 

 and the mammalia they are often larger than the red corpuscles ; they 

 may be recognised by their granular appearance, their peculiar 

 contour, and the irregular shading of their figure. (Pigt. 4 and 6.) 



Blood-Corpuscle*. 



1, Red corpuscle* of human blood, exhibiting their flattened surfaces ; 2, the 

 roe, adherent by their flattened surfaces so as to form rolls ; 3, red corpuscles 

 of frog's blood ; 4, colourless corpuscles of human blood ; 5, the same, enlarged 

 by the imbibition of water. 



They are also to be distinguished from the red corpuscles by their 

 different actions towards chemical re-agents ; they are not attacked by 

 water, but remain in it for a long time without apparent change ; they 

 are not rendered transparent and dissolved by acetic acid ; they only 

 become more decidedly granular under its action, and a kind of 

 nucleus is developed in their centre. As they are in all respects 

 similar to those of lymph and chyle, and as they have the same 

 chemical relations, they have been regarded by many as the corpuscles 

 of the lymph mingled with the blood (Hewson, Miiller) ; others have 

 viewed them as globules of coagulated fibrin (Mandl, Weber) ; and 

 others again with more propriety as blood-corpuscles iu progress of 

 solution or disintegration (Wharton Jones, Hughes liennett). They 

 may be seen in the capillary system of living animals (in transparent 

 structures, as for instance in the frog's foot) swimming with the ordi- 

 nary blood corpuscles, but not so much moving rapidly in the great 

 current of the blood as progressing in close contact with the walls of 

 the vessels in a slower stream. They are not elastic like the ordinary 

 corpuscles, and seem to stick to each other. The exact functions of 

 B corpuscles are still unknown, but there are many facts -\\ln.li 

 i to indicate that there is a decided relation between them and 



I the nutritive or organic life of the tissues. 

 In addition to these cells, which as we have said are comparatively 

 rare, an immense number of what are termed ' red corpuscles,' but 

 which usually present a yellow appearance, are present in the red 

 matter. The blood of numerous animals has been submitted to 

 microscopic examination by Niuwo, Wagner, Gulliver, and other 

 observers, and in general it is found that these red particles have a 

 circular form in all animals constituting the class Mammalia. A 

 remarkable exception to this rule has been shown by Mandl to occur 

 in the corpuscles of the camel tribe. The mean long diameter of the 

 blood-corpuscle* of the Dromedary he found to be the 3254th of an 

 inch, while the mean short diameter was only the 6921st of the same 

 standard. In the Pnco(Auchtnia paeo)ndQnstmco(Anr!i't>;<f iilmnn) 

 the blood-corpuscles scarcely differed in form and size from those of 

 the dromedary, whilst in the Vicuna they were slightly smaller. In 

 structure and magnitudehowever these oval corpuscles of the Cawliilir 

 belong entirely to the mammiferous type ; they hove no perceptible 



nucleus like those of birds, and they are not much more than half 

 the size of even the smallest that have been observed in birds or 



. 



The difference of size in the corpuscles of different mammalia is 

 worthy of notice. The average diameter of those of man, according 

 to Mr. Gulliver, is the 3300th of an inch ; but the average diameter 

 of those of the elephant, according to the same observer, is as much 

 as the 2745th of an inch (which were the largest he observed amongst 

 the mammalia), whilst those of the Napu musk-deer were no more 

 than the 12,325th, and some were as small as the 16,000th of an inch 

 in diameter. There is also an exception to the general statement that 

 the corpuscles of fishes are oval ; in one class, namely the C'yclottomi, 

 or Lamprey Tribe, they are circular. The largest red corpuscles hitherto 

 observed are amongst the reptiles known as the Syren and the Proteus, 

 which are so large as even to be visible to the naked eye as very minute 

 specks. 



There can be no doubt that the red corpuscles go through the same 

 course as other cells. We have undoubted evidence of their rapid 

 regeneration in cases where much blood has been lost, and of the 

 peculiar power which chalybeate medicines have in forwarding their 

 production. The precise method in which they are developed is 

 however not exactly known. 



With respect to the chemical composition of the Mood-corpuscles, 

 the walls ore formed of a substance which has been called globulin, 

 and which is undoubtedly a protein compound. The red colour is 

 due to a pigment which has received the name of Hicmatin, and is 

 inclosed iu the vesicles of globulin. It has been generally assumed 

 that this substance exists in two distinct states in arterial and venous 

 blood, having in the former an excess of oxygen and in the latter an 

 excess of carbon or carbonic acid. Mulder has however shown t hat 

 its elementary composition is the same whether obtained from arterial 

 or venous blood, and that it may be represented by the formula 

 C..H.,, N, 0, Fe ; the following being the analyses from which he 

 deduced it : 



According to 



1 2 3 4 5 the formula. 



Carbon . 66'49 65-91 66-20 6573 65'90 65'84 

 Hydrogen 5'30 5'27 5'44 5'2S 5'27 5'37 

 Nitrogen 10'54 .. 10-46 10'57 10'61 10-40 

 Oxygen . ll'Ol .. 11-15 11-97 .. 1175 



Iron . 6-66 6'58 675 6'45 .. 6'64 



1, 2, and 3 were arterial, and 4 venous ox-blood ; 5 was the mixed 

 blood of a sheep. 



It may be shown by conclusive experiments that the red colour is 

 not dependent on the iron, for that constituent may be removed from 

 the h.i mat in without materially altering its tint, although it is very 

 firmly combined with the four organic elements. The condition in 

 which the iron exists in hecmatin whether as on oxide, a carbonate, 

 a carburet, or in the metallic state has long been disputed. Accord- 

 ing to Liebig the iron of the hicmatin is the moat essential constituent 

 of the blood in relation to the respiratory process. The following is 

 his view of the theory of respiration : " During the passage of the 

 venous blood through the lungs, the globules change colour, anil < \v 

 gen is absorbed from the atmosphere. Further, for every volume of 

 oxygen absorbed, an equal volume of carbonic acid is in most coses 

 given out. The red globules contain a compound of iron, and no other 

 constituent of the body contains iron. Whatever changes the other 

 constituents of the blood undergo in the lungs, this much is certain, 

 that the globules of venous blood experience a change of colour, and 

 that this change depends on the action of oxygen. Now we olwcne 

 that the globules of arterial blood retain their colour in the larger 

 vessels, and lose it only during their passage through the capillaries. 

 All those constituents of venous blood which ore capable of comliinin 

 with oxygen take up a corresponding quantity of it in the l 

 Kxperiments made with arterial serum have shown that when ii 

 tact with oxygen it does not diminish the volume of that gas. Ye 

 blood in contact with oxygen is reddened, while oxygen in absorbed, 

 and a corresponding quantity of carbonic acid is formed. It is evident 

 that the change of colour in the venous globules depends on the com- 

 bination of some one of these elements with oxygen ; ami that this 

 absorption of ><\ygen is attended with the separation of n < 

 quantity of carbonic acid gas. This carbonic acid is not separated 

 from the serum ; for the scrum does not possess tin- properly when in 

 contact with oxygen of giving off carbonic acid. On the rontrary, 

 when separated from the globules it absorbs from half its volume to 

 an equal volume of carbonic acid, and at ordinary temperatures is not, 

 saturated with that go*. Arterial blood, when drawn from the body, 

 i* soon altered ; it florid colour becomes dark red. The florid Mood. 

 which owes its colour to the globules, becomes dark by the action of 

 carbonic acid, and this change of colour affects the globules, for florid 

 blood absorbs a number of gases which do not dissolve in the fluid 

 part of the blood when separated from the globules. It is evident 

 therefore that the globules have the power of combining with gases. 

 The globules of the blood change their colour in different gast->- 

 this change may be owing either to a combination or to a dee. 

 sition. Sulphuretted hydrogen turns them blackish-green, and finally 

 black ; and the original red colour cannot in this case bo restored by 

 contact with oxygen. Here a decomposition has obviously token 



