it is. 



86 HABIT AND INTELLIGENCE. [cHAP. 



Every one knows that waste is constantly going on from 

 animals. It is not so easy to prove that the same is true 

 of vegetables, but it has been ascertained that vegetables, 

 as well as animals, are constantly giving off carbonic acid,i 

 which can only come from the waste of their substance, 

 is the dis- The statement made above, that the compounds which 

 between Compose an organism can be formed nowhere but in the 

 them and organism, will probably be questioned; indeed, many of 

 cme^s'abso- i^ij readers will probably think it is contradicted by those 

 lute? wonderful discoveries of late years in organic chemistry, 

 which have made it possible to form many of the so-called 

 organic compounds from their elements by the inorganic 

 processes of the laboratory. The opinion appears to have 

 gained ground, that there is no absolute distinction between 

 organic and inorganic products, but that with increasing 

 chemical knowledge we may hope to form in the laboratory 

 every substance which we know as a product of vital action. 

 I believe I cannot, however, think so. The most characteristically 

 organic, or vital, products are those of the albuminoid 

 class ; and I cannot think it possible that they can ever 

 be formed by any chemistry except that of the organism 

 of living vegetables. Animals cannot form them. All 

 animals feed either on vegetables, or on other animals 

 which have fed on vegetables ; they receive the albuminoid 

 compounds in their food ; these undergo a process of assimi- 

 lation in the animal's system, which makes them fit to be 

 incorporated with its tissues. 



If the albuminoid and other characteristically organic 

 compounds could be formed by any inorganic chemistry, it 

 woidd be possible for man and his domestic animals to 



lowest organisms lose matter by waste. " In tbe process of j)utrefaction, 

 the researches of Pasteur have shown that so far from oxj'gen being neces- 

 sary to the life of the simple living beings concerned, there are certain 

 forms of infusoria which not only pass their lives without oxygen, but are 

 killed by its presence." (Beale's edition of Todd and Bowman's Physi- 

 ology, p. 19.) Wliat Pasteur here regards as infusoria must, 1 think, be 

 rather vegetable than animal. But whether this is so or not, it is not easy 

 to see how waste can go on in organisms that never come in contact with 

 oxygen, and where, consequently, oxidation is impossible. 



^ Carpenter's Human Physiology, Gth edit. p. 8. It is from this edition 

 1 shall always quote. 



