ORGANIC PRINCIPLES. 71 



Nitrogenized Principles. They all closely resemble one of 

 the most important and certainly the most carefully studied 

 of their number, namely, albumen ; whence they are some- 

 times called Albuminoids. They were regarded by Mulder 

 as compounds of a theoretical radical or base which he 

 called Proteine, and after this chemist are sometimes called 

 Proteine compounds. 



Composition and Properties. 1. Studied, as they gener- 

 ally have been, from a purely chemical point of view, they 

 are regarded by many as solid substances in solution in the 

 fluids, in a condition approximating to this in the semi-solids, 

 and of course as solid in the solids, like the bones and teeth. 

 This view is erroneous, as we shall see that some are natu- 

 rally fluid, some are semi-solid, and some are solid. In this 

 condition they have been found to consist of Carbon, Hydro- 

 gen, Oxygen, Nitrogen, with sometimes a little Sulphur and 

 Phosphorus. The coloring matters contain in addition a 

 small proportion of Iron. By ultimate analysis they have been 

 found to be of indefinite chemical composition* which, indeed, 

 we would be led to expect from the state of continual change 

 in which they exist in the body. By the method em- 

 ployed in arriving at their ultimate composition, even before 

 analysis, they are completely destroyed as organic principles 

 by desiccation, and rendered incapable of exhibiting any of 

 their characteristic properties. The composition of their 

 dry residue only is thus given, while in reality they all con- 

 tain more or less water, which enters into their composition, 

 and deprived of which they cannot be called organic sub- 

 stances. The proportion of water is to some extent variable, 

 but confined within tolerably narrow limits. 2 



2. The organic principles never exist alone, but always in 



1 ROBIN and VERDEIL, op. tit., tome iii., p. 147. 



2 For a further discussion of this important subject, see an article by the author 

 in the American Journal of the Medical Sciences, October, 1863, On the Organic 

 Nitroyenized Principles of the Body, with a New Method for their Estimation in 

 the Blood. 



