. The chemistry of agriculture, for students and farmers. Agricultural chemistry. BLOOD 315 being somewhat amoeboid in character (Fig. 79). They can pass through the walls of the ca])illaries and wander through the tissue fluids. These leucocytes are composed of proteins, glycogen, lecithin, fat, and phosphates. They are said to serve as blood scavengers, carry- ing away and absorbing undis- solved substances in the blood such as bacteria. Apparently whenever a wound gives entrance to bacteria the w^hite corpuscles swarm to that place and help to destroy them. Although this fact has not been d
. The chemistry of agriculture, for students and farmers. Agricultural chemistry. BLOOD 315 being somewhat amoeboid in character (Fig. 79). They can pass through the walls of the ca])illaries and wander through the tissue fluids. These leucocytes are composed of proteins, glycogen, lecithin, fat, and phosphates. They are said to serve as blood scavengers, carry- ing away and absorbing undis- solved substances in the blood such as bacteria. Apparently whenever a wound gives entrance to bacteria the w^hite corpuscles swarm to that place and help to destroy them. Although this fact has not been definitely proved, it is still a reasonable belief. {d) Coagulation.—On expos- ure to the air blood clots or coagu- lates, and there is formed a mass of corpuscles matted together with a fibrous substance. The cause of this clotting is not defi- nitely known, but the theory has been advanced that an enzyme with the help of a calcium salt acts on fibrinogen, a soluble pro- tein, changing it to fibrin, an insoluble protein. Fibrin is a white, fibrous material which en- tangles the corpuscles into a clot. The liquid remaining after the clot forms is called serum, and is merely plasma w^ithout the fibrin- ogen. By beating fresh drawn blood the fibrin can be obtained free from corpuscles. The speed of coagulation is hindered by cold, by a 10 per cent, solution of ammonium oxalate or of sodium chloride. It is hastened by heat, ferric chloride, and alum. Speed of coagulation also varies with animals. The blood of horses clots very Fig. 79.—Small blood-vessel, showing how leucocytes pene- trate the wall. (G. Bachman.). Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Stoddart, Charles William, 1877-. Philadelphia, New York, Lea & Febiger
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Keywords: ., bookcollectionam, booksubjectagriculturalchemistry, bookyear1915
