BLOOD 403 



animals, and vary considerably in size and shape in different groups of the vertebrata. 

 They are always, however, flattened disc-like bodies, oval or circular in outline, and 

 with or without a nucleus. These corpuscles consist apparently of an albuminoid 

 substance, enclosing a red fluid. This fluid is now recognised as a definite crystallisable 

 compound, containing iron, and termed hemoglobin, htemoglobulin or hamatoglobulin. 

 Haemoglobin may be resolved into two substances called globulin and hamatin. The 

 so-called blood-crystals vary in shape, and are in many cases characteristic of the 

 animal from which the blood was taken. The haemoglobin of the dog has been found 

 to contain 



Carbon 53*85 



Oxygen 2f'84 



Hydrogen 7'82 



Nitrogen 16-17 



Sulphur 0-39 



Iron . 0-43 



100-00 



The liquor sanguinis, or colourless liquid in which the corpuscles freely float, 

 contains fibrin (or rather two albuminous substances "which readily form fibrin, and 

 are called paraglobulin and fibrinogeri), albumen, fatty matter, and certain saline sub- 

 stances. On die coagulation of blood, the fibrin separates in a gelatinous form, 

 carrying with it the red corpuscles ; this mixture of fibrin and corpuscles forms the 

 clot, or crassamentum, whilst the remainder of the blood constitutes the liquid known 

 as serum. If the warm blood be switched with a bundle of twigs as it flows from the 

 veins, the fibrin concretes and forms long fibres and knots, while it retains its usual 

 appearance iu other respects. The clot contains fibrin and colouring-matter in various 

 proportions. Berzelius found, in 100 parts of the dried clot of blood, 35 parts of 

 fibrin, 58 of colouring-matter, 1-3 of carbonate of soda, 4 of an animal matter soluble 

 in water, along with some salts and fat. The specific gravity of the serum varies from 

 1-027 to T029. It forms about three-fourths of the weight of the blood, has an 

 alkaline reaction, coagulates at 157 F. into a gelatinous mass, and has for its leading 

 constituent albumen to the amount of 8 per cent., besides fat, potash, soda, and salts 

 of these bases. Blood does not seem to contain any gelatine. Fat and sugar are 

 found in blood, the quantities varying with the health of the animal. For a very full 

 account of the researches made by chemists on blood, see ' Watts's Dictionary of 

 Chemistry.' 



The red colouring-matter called hematosine may be obtained from the cruor, or 

 haemoglobin, by washing with cold water and filtering. Professor Stokes, in a paper 

 ' On the Reduction and Oxidation of the Colouring -Matter of the Blood,' has published 

 some very curious results. By spectrum-analysis he has been led to infer that the 

 colouring-matter of blood, like indigo, is capable of existing in two states of oxida- 

 tion, distinguishable by a difference of colour and a fundamental difference in the action 

 on the spectrum. It may be made to pass from the more to the less oxidised state, by 

 the action of suitable reducing agents, and recovers its oxygen by absorption from 

 the air. This colouring-matter in its' two states of oxidation, Professor Stokes 

 proposes to call scarlet cruorine and purple cruorinc. Proceedings of the Royal Society, 

 vol. xiii. p. 355 (1864). 



Mr. Sorby has also published in the ' Quarterly Journal of Science.' No. VI., April 

 1865, a paper ' On the Detection of Blood Stains by Spectrum-Analysis,' in which ho 

 shows how it may be employed with great reliance in cases of the highest judicial 

 importance. These two papers should be consulted. 



Blood may be dried by evaporation at a heat of 130 to 140, and in this state has 

 been transported to the colonies for purifying cane-juice. It is used for making 

 animal charcoal in the Prussian-blue works, and, by an after-process, a decolouring 

 carbon. It is employed in some Turkey-red dye-works. Blood is a powerful manure. 



Mr. Pillans, in 1854, took out a patent for the separation of the colouring-matter of 

 the blood, by which he obtained readily 1st, the clot, in a comparatively dry state, 

 comprising haematosine, with a portion of serum and all the fibrin ; 2nd, a portion of 

 serum, highly coloured with hsematosine ; 3rd, the clear serum. 



The blood, in small fragments, is dried on wirowork or trays, at a less temperature 

 than will coagulate the haematosiue, so that, when dry, it may be soluble in water ; 

 110 to 115 is the temperature recommended. 



The clear serum is dried and ground and in a fit state to be used as albumen, and 

 may be employed by the printers of textile fabrics for fixing ultramarine blue and 

 other colours, or as a substitute for egg albumen, both in printing colours and in 

 refining liquids. 



DO 2 



