BLOOD. 



[ 102 ] 



BLOOD. 



sotriton punctatus) , 1. 1-830; Amphiuma,\. 

 1-340. 



Fishes, Cai-p {Oyprinus carp{<)),\.\-2\i:2, 

 b. 1-3429; Eel {AnquiUa vulgaris), \. 1-1745, 

 b. 1-2842; Jack {Esox lucius), 1. 1-2000, 

 b. 1-350.5; Miller's Thumb {Cottm </ohio), 

 1. 1-2000, b. 1-2900; Perch {Percafliwia- 

 tilis), 1. 1-2099, b. 1-2824 ; Tench {Ct/prinas 

 Tinea), 1. 1-2286, b. 1-2722. 



The colourless corpuscles do not vary so 

 much in size in diftereut animals as is the 

 case with the coloured corpuscles. Those 

 of the human blood are about 1-2500" in 

 diameter. 



A third corpuscular element of the blood, 

 related to its formation, is described by 

 Norris. 



The red corpuscles of blood consist che- 

 mically of Htemoglobiue ( Haematoglobu- 

 line) ; and this is composed of a colouring- 

 matter — hsematine, and an albuminous sub- 

 tance — globuline. They are readily altered 

 in form by most liquids; those of less spe- 

 cific gravity than the liquor sangmnis dis- 

 tend them, rendering them larger, paler, and 

 more transparent, and effacing the lenticu- 

 lar appearance and the elHptical form when 

 present. If a small quantity of water be 

 added, the corpuscles in motion are seen to 

 be highly elastic, becoming altered in shape 

 when coming into contact with each other, 

 but resuming their form when free. If the 

 liquid be added in large proportion, the en- 

 velope or cell -membrane becomes extremely 

 thin and pale, until at last it is no longer 

 distinguishable ; sometimes it bursts. These 

 phenomena are the residt of endosmosis. 

 The red corpuscles, however, are not all 

 equally acted upon : some are much more 

 affected than others ; some even appear 

 almost entirely to resist the action of en- 

 dosmotic agents, and are found but little 

 altered, even when the blood is mixed with 

 a large proportion of water. Although 

 water and other endosmotic agents distend 

 the coloured corpuscles, and render their 

 envelopes so extremely transparent that 

 they can no longer be recognized, yet many 

 of them may be restored to view by the 

 addition of reagents which either act cxos- 

 motically, colour them, or rendcjr them 

 opaque — as solution of iodine, of bichloride 

 of mercmy, and various other salts. Dilute 

 acids act nearly in the same manner as 

 water, but much moi-e rapidly. Dilute 

 solutions of alkalies produce the same effect, 

 but soon dissolve them completely. Solu- 

 tions of neutral salts act exosmotically, 



rendering them smaller, more flattened, and 

 producing wrinkles, folds, or a granular ap- 

 pearance in the enveloping membrane. Fre- 

 quently also they appear covered with little 

 points, giving them an elegant stellate 

 aspect; tins stellate or crenate appearance 

 is not uufrequently seen immediatelv that 

 fresh blood is examined under the micro- 

 scope, especially at the margins of the drop. 

 Two principal conditions are especially 

 favourable to its production, viz. a concen- 

 trated state of the liqidd, and an increase 

 in the proportion of alkaline chlorides ; the 

 action of alcohol also tends to produce this 

 condition. 



The comparative size of the corpuscles 

 in the races of man is treated of by Kich- 

 ardson (3/. M. Jn. 1877, xvii. 212). 



The corpuscles of the blood of the hepatic 

 vein are smaller, more spherical, Avithout 

 the central depression, and resist the action 

 of water for a longer time than the ordinary 

 corpuscles ; similar corpuscles are also met 

 with in the spleen. These are by some 

 regarded as young newly formed corpuscles ; 

 while those of the portal vein possess the 

 ordinary characters. 



Matters which coagulate the albuminous 

 matter of the red corpuscles, such as alcohol, 

 tannic acid, and creosote, also heat, alter 

 their form, giving rise to the production 

 of tail-Uke processes, with adherent minute 

 globides, wJiich also cover the surface of 

 the corpuscles.' And by pressui'e the latter 

 are broken up into a number of similar 

 globules. 



It is a disputed point whether the red 

 corpuscles have a cell-wall or not. The 

 action of osmotic reagents tends to show 

 that they have ; and " the membrane can 

 be distinctly seen with 1000 diameters in 

 the newt's corpuscle after the addition of 

 magenta and tannic acid " (Rutherford). 

 Beale shows that they may be crushed into 

 fragments by pressure on the cover ; but 

 as the haemoglobiue surely coagulates, this 

 is accounted for ; and moreover, the hsemo- 

 globine is readily soluble in water and in 

 serum ; and it seems difficult to understand 

 how it resists the solvent action of the serum 

 unless defended by a cell-wall. 



The red corpuscles of the blood contain 

 or consist of Ilajmoglobine (ILematoglo- 

 buline). This may be obtained in a crys- 

 talline state by adding 6ther by drops to 

 defibriuated blood, and shaking until the 

 bright and opaque colour of the blood is 

 replaced by that of ^ syrupy transparence. 



