ORGANIC CHEMISTRY 465 



in the dietary necessary for living organisms. But protoplasm 

 is believed to consist of colloid material in which not only carbon, 

 hydrogen and oxygen are elements, but nitrogen is an essential 

 component. Phosphorus is also a constituent of some proteins, 

 and indispensable at some stages of development. Now form- 

 aldehyde is a very active substance which readily enters into 

 chemical reactions of all kinds, and in the presence of ammonia 

 is converted into a definite basic substance, hexamethylene- 

 tetramine, which under the various names hexamine, etc. has 

 long been used in medicine. Whether the minute and highly 

 diluted quantities presumably formed in the process described by 

 Professor Moore would yield hexamethylene-tetramine by contact 

 with a mixture of gases containing ammonia it is difficult to say, 

 but for the sake of argument it may be assumed that some 

 organic compound containing nitrogen would be produced. 

 We may even go further and suppose that, by a series of changes 

 the nature of which cannot now be even conjectured, a complex 

 colloidal protein was actually formed. We may in the present 

 state of knowledge safely enquire What then ? No chemist 

 will be induced to believe that a pulpy mass of one or more 

 aminoacids, no matter how complex or how associated with 

 saline electrolytes, will cease to exhibit the characters which 

 belong to chemical compounds in general, and acquire of its 

 " own mere motion " the power of utilising and controlling 

 energy supplied from external sources in such a way as to give 

 rise to the cycle of events exhibited in every particle of living 

 substance, from the amoeba onwards. 



Something has been made of a supposed resemblance between 

 cell membranes and the curious forms which some of the very 

 simplest organisms assume and the films and cavities formed by 

 inorganic colloids in the process of drying, or when in contact 

 with other matters in a different state of hydration. There is 

 just as much resemblance in such case as is to be found between 

 the forms of fossil plants in the more ancient rocks and the 

 foliaceous tracery produced by frost on the pavements in winter. 

 It has even been suggested that some of these impressions in the 

 palaeozoic rocks may after all have been left by frost, and not 

 by the fronds of ancient ferns. No one, however, supposes that 

 if it were so these forms represent the beginning of life. 



But protoplasm cannot be thought of merely as a solution of 

 mixed colloids and saline electrolytes. It must consist of aggre- 



2H 



