APPENDIX I. 



Very varying results are sometimes obtained in many of 

 these experiments with different material. As instances of 

 extreme variations we may mention two of our experiences. 



On one occasion the shoots of Onobrychis sativa which 

 had been kept for the usual time in the dark contained 

 scarcely a trace of amides, and on another no traces of tartaric 

 acid could be detected in beetroot juice, which commonly 

 contains enough of this acid to be easily detected without any 

 special skill in this kind of analysis. 



We have therefore added the following notes on our 

 experiences in conducting these experiments with students, 

 and given the numbers obtained for the quantitative results of 

 fairly representative cases. 



We have tried as far as possible to arrange the quantitative 

 experiments so that fairly accurate work wiU clearly demon- 

 strate the principles involved, but in Such cases as the 

 estimation of proteids and mixed sugars very careful work 

 is essential. 



Chapter X. p. 231. Proteids, etc. 

 Qualitative. 



The NaOH extract will contain large quantities of proteids 

 insoluble in water and give a copious precipitate when neutral- 

 ised. 



