COMPOSITION OF THE BLOOD. 521 



animals, and the soft vascular structure of plants ; 

 but that the movements of life are slow and feeble 

 in the hard woody fibre, and almost wholly ab- 

 sent in the earthy matter of bones. Fluidity, 

 then, which is only another name for mobility, 

 is absolutely essential to the manifestations of 

 life. 



According to the latest analyses of human 

 venous blood, it has been found to consist of 

 about 790 parts of water in 1000, and the remain- 

 der of albumin, fibrin, colouring matter, oily 

 and saline ingredients. From which it is obvious 

 that as water is composed of eight parts by 

 weight of oxygen to one of hydrogen, and also 

 forms about \ of the organized part of the blood, 

 oxygen must constitute by far the greater pro- 

 portion of its substance ; the remainder being 

 carbon and nitrogen, with nearly 1 per cent, of 

 saline matter. 



From the ternary and quaternary combi- 

 nations of oxygen, hydrogen, carbon, and nitro- 

 gen, organic molecules are generated, which 

 form the proximate constituents of all living 

 bodies, whether fluid or solid, from the simplest 

 plant or gelatinous animalcule up to man. They 

 have been found in the blood, chyle, chyme, 

 milk, fat, saliva, bile, pancreatic, and gastric 

 juice, the seminal fluid, the yolk and albumin of 

 the egg, in all animals ; in the sap of plants, 

 and much more abundantly in the cambium, 



