AND PHYSICAL FORCES 17 



it had come." " Thus," Dumas also says, " is the mysterious circle 

 of organic life upon the surface of the globe completed and 

 maintained ! The air contains or engenders the oxidised sub- 

 stances required — carbonic acid, water, nitric acid, and ammonia. 

 Vegetables, true reducing apparatus, seize upon the radicals of 

 these, carbon, hydrogen, azote, ammonium ; and with them they 

 fashion all the variety of organic or organisable matters which 

 they supply to animals. Animals, again, true apparatuses of com- 

 bustion, reproduce from them carbonic acid, water, oxide of 

 ammonium, and azotic or nitric acid, which return to the air to 

 reproduce the same phenomena to the end of time." 



Thus it would appear that the most simple not-Uving or mineral 

 constituents coming into relation with one another in the presence 

 of pre-existing protoplasm, appear, for aught we know to the 

 contrary, to fall at once into those subtle combinations which 

 constitute the basis of ' living ' matter. The rapidity of the 

 process mocks and defies all theoretical explanation. Here, at all 

 events, there seems to be no laborious process of synthesis — no 

 long chain of substitution compounds — before the final product 

 is evolved. 



But the property of decomposing ammonia and of feeding upon 

 elementary mineral substances is by no means confined to the 

 higher plants. The same power is possessed by Conferva vulgaris 

 and other low Algae, as was demonstrated by Bineau more 

 than fifty years ago ' ; while nearly ten years afterwards it was 

 ascertained by Pasteur that some of the lowest kinds of fungi, 

 the Mucedineae, were capable of growing and multiplying in 

 a solution of sugar and tartrate of ammonia, to which a trace of 

 some phosphate had been added. Referring to Pasteur's observa- 

 tions, Baron Liebig said : — " It is astonishing that this discovery has 

 not attracted more attention in regard to a special point, for it 

 comprises a fact of very great significance for physiology, viz., the 

 formation of albuminates in plants, respecting which we are in 

 possession of scarcely anything beyond conjecture ; hitherto this 

 has been regarded as one of the greatest mysteries of organic 

 nature. ... If yeast cells, placed in a mixture of ammonia, 

 tartaric acid, sugar, and phosphate, could propagate and multiply, 

 it is evident that an albuminate must have been formed from the 



' Mem. de I'Acad. des Sciences de Lyon, t. iii, 1853. 



2 



