160 On the Effect of Madder Root 



of the blood naturally exerted a stronger at- 

 traction for the colouring matter of madder, 

 than the phosphate of lime, it might be de- 

 prived of the tint by a chemical power. In 

 drd^ to prove this, as far as I could by ex- 

 periment, I took one dram of the phosphate of 

 lime tinged, as in Dr. Rutherford *s experi- 

 ment, and exposed it for half an hour to the 

 action of two ounces of fresh serum, at the 

 temperature of 98 degrees. By this operation, 

 the serum gradually acquired a red tinge, 

 whilst the phosphate of lime, was proportiona- 

 bly deprived of colour. In a comparative ex- 

 periment, a similar quantity of tinged phosphate 

 of lime, was exposed to the action of dis- 

 tilled water under similar circumstances ; but 

 no change took place. The knowledge of this 

 •strong affinity, in the serum for colouring 

 matter, affords an easy and simple explanation 

 of the effects of madder on the bones, upon 

 the principle of chemical attraction. 



Thus, when an animal has madder mixed 

 w^ith its food, the blood becomes highly 

 charged with it, and imparts the superabun- 

 dant colouring matter to the phosphate of lime, 

 contained in the bones already formed ; as it 

 circulates through them and moistens them 

 throughout. But as soon as an animal has 

 ceased to receive the madder, and the blood 



