CHEMICAL PHYSIOLOGY. 51 



succinic and lactic acid, and perhaps also volatile fatty 

 acids and sugar. In the progress of the involution of 

 the thymus the amount of sodium contained in it is 

 nearly doubled. 



The thyroid contains nearly the same chemical con- Thyroid 

 stituents as the thymus. It would be very confusing 

 that the constituents of glands of the most varied 

 connection and situation are identical, were we not 

 reminded that the denned ingredients are perhaps only 

 one fourth or one sixth of the whole of the ingre- 

 dients, and that specific differences may therefore be 

 discovered upon the ingredients which at present are 

 undefined. The thyroid is said to contain mucine, par- 

 ticularly when in the state termed colloid degeneration ; 

 it then also contains cholesterine . When containing 

 brown fluids, in the disease termed struma, a sediment 

 of blood-corpuscles is mostly present, which, however, 

 contain only decomposed hematocrystalline in the form 

 of hematine. 



The renculi yield many curious coloured reactions. 

 Their alcoholic or ethereal extracts become yellow and 

 red when exposed to the air, and show a green fluor- 

 escence due to renculine ; their watery extracts are 

 coloured red by iodine, and blackish blue by iron- 

 chloride. They contain leucine, but the presence of 

 other particular biliary matters which has been alleged 

 is at present not proved. In certain chronic diseases 

 (Addison's disease, or bronzed skin), in which the 

 skin is more or less copper or brown-coloured, the 

 suprarenal capsules are specifically diseased. 



The ovaries are composed of the stroma, the Graafian 



