24 VELOCITY OF REACTIONS 



we do not know their composition and therefore are, 

 so far, unable to prepare them. These^organic 

 products have been characterized above. 



/In most cases these substances are very unstable, 

 so that they are rapidly decomposed, especially at 



igher temperatures. This spontaneous decomposi- 

 tion has often been regarded as characteristic of these 

 substances, but closer investigation indicates, as we 

 /will see below, that they behave just in the same 

 manner in their reactions as do well - defined 

 substances known from the general chemistry. 

 Even from inorganic chemistry we know a great 

 number of products which are stable only at low 

 temperatures. 



As regards the progress with time of this decom- 

 position it behaves precisely as an ordinary mono- 

 molecular reaction, as the following figures and 

 diagrams indicate. They give the rate of destruction 

 of tetanolysin at 49-8 C. and of a haemolytic anti- 

 body, found in the serum of a goat after injection of 

 blood-corpuscles from a rabbit, at 51 C. The law 

 of monomolecular reactions states that the curves 

 representing the logarithm of the quantity of the 

 substance in decomposition, e.g. the tetanolysin or 

 the haemolytic antibody, as a function of time, is a 

 straight line (cf. p. 6). 



