THE BLOOD. 151 



the blood contains the elements of phosphate of iron and of lime, 

 and of carbonate of lime, and also of phosphate of magnesia, 

 united in a manner different from their combination in the salts. 

 M. Raspail, seven years ago, showed that certain coagulable sub- 

 stances will protect a metal from the strongest re-agent that 

 a mixture of oil and the salts of iron will afford no signs of the 

 metal till some days after it has been placed in acidulated ferro- 

 chyazate of potass. Rose obtained the same result on mixing 

 albumen or gelatine with peroxide of iron. But Dr. Engelhart 

 has shown iron to exist in blood, by the usual liquid tests, after 

 passing a stream of chlorine through a solution of red particles. 6 



" The last constituent principle of the blood to be noticed, is 

 the plastic lymph, formerly confounded with the serum. This has 

 been called the basis of the crassamentum, the glutinous part, the 

 fibre or fibrous matter of the blood." It is now termed Jibrin. 



" It is properly denominated plastic, because it affords the chief 

 materials from which the similar parts, especially the muscles, are 

 immediately produced ; nourishes the body throughout life ; re- 

 pairs wounds and fractures in an extraordinary manner ; fills up 

 the areae of large blood-vessels when divided f ; and forms those 

 concretions which accompany inflammations s, and that remark- 

 able deciduous membrane found in the recently impregnated 

 uterus for the attachment of the ovum." 



We will now consider the coagulation of the fibrin more 

 minutely. 



Blood coagulates when it has escaped from the body, whether 

 warm or cold, in the air or in vacuo, diluted within certain limits 

 or undiluted, at rest or in motion. Within the vessels, rest, which 

 causes a cessation of intercourse between the motionless portion 

 and the general mass, always disposes it to coagulate. Yet its 



e Edinburgh Medical and Surgical Journal, Jan. 1827. Engelhart's Essay 

 obtained the prize at Gottingen in 1825. 



f " T. F. D. Jones, On the process employed by nature in suppressing the he- 

 morrhage from divided &c. arteries. London. 1 805. 8vo. Translated into 

 German, and supplied with notes by G. Spangenberg. Hanov. 1813. 8vo." 



s " Such are those spurious membranes found exuded on the surface of inflamed 

 viscera, v. c. those cellular connections between the lungs and pleura after 

 peripneumony, and the tubes observed within the bronchia after croup ; such also 

 are those artificial ones, called, from their inventor, Ruyschian, and made by 

 stirring fresh blood about with a stick." Although they are fibrinous, they contain 

 a fluid in their cells that is albuminous. 



