in its Relations to Physiology. 415 



beginning of the task of the chemist. I felt it right to reject all such re- 

 sults, and to urge incessantly upon chemists that figures are of no use 

 whatever unless connected with definite questions ; that these methods 

 could prove of no avail to physiology ; and that our labours, to be of 

 any value, must be available as preparatory to those of physiologists. 



I had an undoubted right to do this, as much as a man who perceives 

 his fellow-travellers are pursuing a wrong road has to warn them to re- 

 trace their steps, more especially as one who has devoted his life to the 

 improvement of this department of science. Must I remind Berzelius 

 what has been done during the last twenty years in the chemical school 

 at Giessen ? He has been living all this time, and ought not to forget it 

 so easily, even should it be forgotten by a younger generation. 



I fear not to speak of my own labours, from hippuric acid to my re- 

 cent investigation of urine, nor to mention those which I have made in 

 common with Wohler. I must remind Berzelius that, from the very 

 outset of my career, all my efforts have been directed to the attainment 

 of a definite object. T feel almost ashamed to recall to Berzelius' mind 

 how much has sprung from my endeavours, and to remind him of the 

 advantages that have been derived from my methods, and from the in- 

 troduction and adoption of my apparatus. But I may be allowed to 

 quote a passage from a paper on some nitrogen compounds, published 

 ten years ago (Annalen der Chemie and Pharm., Bd. x., s. 3), since this 

 will tend to render my object and purpose more clear and intelligible to 

 him and also to my readers. 



" Our insight into the mysterious processes of the animal organism 

 will acquire a very different import if, instead of resting satisfied with 

 decomposing the substances occurring in the various organs, into nu- 

 merous other combinations, the properties of which teach us nothing, 

 we follow their alterations and transformations, step by step, through 

 elementary analysis, without heeding (for the moment) their properties ; 

 whilst in this manner, we arrive from one link to the other, we indubi- 

 tably approach the point more and more from which the chain pro- 

 ceeds ; infinitely distant though this point may be, yet we approach it. 



" We know that the oxygen of the atmosphere stands in a definite 

 relation to the blood in the respiratory process ; we can show the alter- 

 ations which the air undergoes, and observe the phenomena taking 

 place in the lungs ; but if the science of chemistry does not succeed in 

 following up in the animal body all the alterations which take place 

 in the organs, and in the substances acting upon the organs, and oper- 

 ated upon by them in return, and in obtaining an insight into these 

 alterations, it is not worth while to occupy ourselves with them. So 



3 H 



