LIFE: ITS NATURE, OEIGIN AND MAINTENANCE 13 



evolution become complete cells, fulfil functions in many respects similar 

 to those fulfilled by the nucleus of the more differentiated organism. 



A similar anticipation regarding the probability of eventual synthetic 

 production may be made for the proteins of the cell-substance. Con- 

 siderable progress in this direction has indeed already been made by Emil 

 Fischer, who has for many years been engaged in the task of building 

 up the nitrogenous combinations which enter into the formation of the 

 complex molecule of protein. It is satisfactory to know that the signifi- 

 cance of the work both of Fischer and of Kossel in this field of biological 

 chemistry has been recognised by the award to each of these distinguished 

 chemists of a Nobel prize. 



The elements composing living substance are few in number. Those 

 which are constantly present are carbon, hydrogen, oxygen, and nitrogen. 



With these, both in nuclear matter and also, but to a 



The chemical con- i egg d e rr ree in the more diffuse living material which 



stitution of living 



substance. we know as protoplasm, phosphorus is always 



associated. ' Ohne Phosphor kein Gedanke ' is an 

 accepted aphorism ; ' Ohne Phosphor kein Leben ' is equally true. 

 Moreover, a large proportion, rarely less than 70 per cent., of water 

 appears essential for any manifestation of life, although not in all cases 

 necessary for its continuance, since organisms are known which w T ill bear 

 the loss of the greater part if not the whole of the water they contain 

 without permanent impairment of their vitality. The presence of 

 certain inorganic salts is no less essential, chief amongst them being 

 chloride of sodium and salts of calcium, magnesium, potassium, and iron. 

 The combination of these elements into a colloidal compound represents 

 the chemical basis of life ; and when the chemist succeeds in building up 

 this compound it will without doubt be found to exhibit the phenomena 

 which we are in the habit of associating with the term ' life.' * 



The above considerations seem to point to the conclusion that the 

 possibility of the production of life i.e., of living material is not so 



remote as has been generally assumed. Since the 



Source of life. The experiments of Pasteur, few have ventured to affirm 

 possibility of spon- * . , . . . , , . , 



taneous generation. a belief in the spontaneous generation 01 bacteria and 



monads and other micro-organisms, although before his 

 time this was by many believed to be of universal occurrence. My 

 esteemed friend Dr. Gharlton Bastian is, so far as I am aware, the only 

 scientific man of eminence who still adheres to the old creed, and 

 Dr. Bastian, in spite of numerous experiments and the publication of 

 many books and papers, has not hitherto succeeded in winning over many 

 converts to his opinion. I am myself so entirely convinced of the 

 accuracy of the results which Pasteur obtained are they not within the 



* The most recent account of the chemistry of protoplasm is that by Botazzi (Das 

 Cytoplasma u. die Korpersafte) in Winterstein's Handb. d. vergl. Physiologic, Bd. I., 

 1912. The literature is given in this article. 



