134 BASIC BODIES. 



no odour; all are soluble in alcohol, a few in water, and none that 

 we have here considered, in ether ; although most alkaloids act on 

 vegetable colours, none of those under consideration, excepting 

 creatinine and sarcosine, exhibit this property. 



Their salts are almost universally crystallisable and soluble in 

 water as well as in alcohol ; with bichloride of platinum their hydro- 

 chlorates form compounds which are either insoluble or difficult 

 of solution ; their oxygen salts cannot exist without 1 equivalent 

 of water. The most strongly basic alkaloids are precipitated by 

 tannic acid from dilute aqueous solutions. 



Although many of the substances which we shall have to con- 

 sider in this group do not possess any basic properties, and there- 

 fore do not, strictly speaking, belong to it, we have arranged them 

 together, partly on account of the analogy exhibited in their 

 empirical composition, and partly, because in a physiological point 

 of view, they exhibit tolerably equal values, that is to say, they are 

 derivatives of nitrogenous tissues. The bodies which we shall now 

 consider, are : 



Creatine C 8 H 9 N 3 O 4 



Creatinine C 8 H 7 N 3 O 2 



Tyrosine C 16 H 9 N O 5 



Leucine .... C 12 H n N O 4 



Sarcosine C 6 H ? N O 4 



Glycine (Glycocoll) C 4 H 5 N O 4 



Urea C 2 H 4 N 2 O 2 



Xanthine C 5 H 2 N 2 O 2 



Guanine C 10 H 5 N 5 ^O 2 



Allantoine C 8 H 5 N 4 O 5 



Cystine C 6 H 6 NS 2 O 4 



Taurine C 4 H 7 NS 2 O 6 



CREATINE. C 8 H 9 N 3 O 4 . 

 Chemical Relations. 



Properties. This body forms transparent, very brilliant crystals, 

 belonging to the clinorhombic system and containing 2 atoms of 

 water of crystallisation ; it is of a bitter, strongly pungent taste, 

 and irritates the pharynx; it loses its 2 atoms of water at 100, and 

 at a higher temperature becomes decomposed ; it dissolves in 74*4 

 parts of cold water, and in boiling water in such quantity that, on 

 cooling, the solution becomes consolidated into a mass of delicate 



