41'jfe ON THE EFFECT OF MADDER ROOT, ScC, 



the phofphate of lime, and the bones refume their natural 



wJiitenefs. In thort, the bones are at one time d}'ed by the 



colouring matter, at another time bleached by the ferum. 



Phofphate while WhiJft I have attempted to explain the prob ble manner in 



fufpended does i-l,ii it/. i- •■ 



not ftrongly wtnch the bones, alreadj/ formed m an animal, at one time 



take the CO- receive, and at another are deprived of the colouring matter 

 louring matter. ^^ madder, I by no means miend to aliert that the phofphate 

 of lime does not acquire a fimilar colour during its folution in 

 the ferum, or at the time it is precipitated from it to enter into 

 the compofition of the bones; the fad is indifputable. I have, 

 however, found from fome experiments lately made upon a 

 hen during oviparation, that only a flight tinge can be com- 

 municated to the fliell, formed whilft a large quantity of 

 Example in colouring matter is circulating with the blood. So flight indeed 

 ' is the blufli, that it would not be feen by a common obferver, 



unlefs contrafted with a natural egg: which is probably the 

 reafon why it has, I believe, been denied by phyfiulogifts, 

 that the fliell of an egg is altered by the exhibition of madder. 

 If this may be confidered as a teft of the quantity of colouring 

 matter, which the phofphate altradls at the time it is feparated 

 from the blood,' it forms anolher flrong argument againft the 

 theory, which Dr. Rutherford, and all preceding ph)fiologills 

 liave adopted ; for, confiftent with this fa6t, the bones fhould 

 never exhibit more than a flight blufli. When explained upon 

 the principle of chemical attraftion, we lee that the phenomena, 

 exhibited by the bones of "an animal, by giving or withholding 

 madder root, give no fupport to the opinion that the various 

 parts of the body continually undergo an imperceptible change ; 

 and I confider it a fortunate circumflance for that dodrine 

 The doaiineof that fo iimple an explanation of the efTed of madder can be 

 a lapid and con- -^gj^^ jr^j. ^j^jK^ f^ fpecious a favt has been confidered, by 

 tinual change is ° , ... . . . 



not fupported thehigheft au:hoiities, as complete proof of the imperceptible 



by the fads of renovation of parts ; the rapid change in the conftituent 



bones tinged by , r . i i-i , ■ • , .t 



the madder. elements or the bones, which the communication and dil- 

 appearance of the colour indicates, mufl: have appeared 

 afionifliing to every phyfiologift. Of (his I cannot give you 

 a ftronger inftance than in the words of Mr. J. Bell.* 

 Nothing," fays he, " can be more curious than this continual 

 renovation and change of parts even in the hardeft bones. 

 We are accuftomed to fay of (he whole body, that it is daily 



* Anatomy of the bones, &c. p. 13. 



changed ; 



