434 Observations on Organic Chemistry 



value in themselves, to enable him to form a satisfactory theory. He 

 agitates blood with air, and as he afterwards detects a trace of carbonic 

 acid in the air, although without perceiving the slightest absorption of 

 oxygen, he is satisfied that this evolution of carbonic acid suffices to 

 explain the respiratory process, and yet a handful of wet sawdust or a 

 leaf would have produced exactly the same result. How would it be, 

 supposing that blood would not in this way yield carbonic acid when 

 removed from the organism ? 



Innumerable experiments have been made to prove the nutritive 

 properties of carbonic acid for plants, which all gave a negative result. 

 Although it was most positively known that carbonic acid is absorbed 

 by the green-plant, that under the influence of light it becomes de- 

 composed in the organism ; that its carbon is assimilated and oxygen 

 eliminated in a gaseous form. The experiments I allude to have no 

 value whatever, because the experimentalists disregarded altogether the 

 conditions necessary for the absorption and assimilation of carbonic acid 

 by the plants, excluding everything, and neglecting every precaution, 

 indispensable to the success of their experiments. 



We hear every day of experiments of a similar kind. Thus, to ascer- 

 tain whether sugar is capable of being transformed into fat in the living 

 animal body, a dozen pigeons are stuffed daily with a quantity of sugar, 

 which acts upon them like a medicinal substance, or a poison, and 

 when after the lapse of from six to ten days they die of starvation, the 

 experimentalist strangely expects to see them filled with fat, and is 

 amazed to find himself disappointed. Thus, without knowing the condi- 

 tions of the formation of fat in the animal organism, without stopping 

 to inquire whether any conditions are required, the experiment is 

 commenced by excluding every thing which would render its success 

 possible. A state of artificial disease is produced in the animals ; all 

 nourishment is most carefully withdrawn from them, and thus they 

 are deprived of everything necessary for the formation of blood— for 

 the support of the vital processes, and, consequently, of that action 

 which causes the formation of fat. By means of these cruel and wretch- 

 ed experiments these gentlemen believe they are able to prove that 

 sugar, a non-nitrogenous substance, is incapable of being converted 

 into fat, another non-nitrogenous substance. Such experiments prove 

 nothing whatever, except the ignorance and total incapacity of the 

 experimentalist to pursue these investigations. 



Everywhere, and in all cases where we can succeed in ascertaining, 

 from nature herself, the conditions of a phenomenon, our inferences 

 possess a far higher value than they could ever acquire were they 



