On fresh 



On air-dried 



leaves. 



leaves. 



76-65% - 





3-11 



13-30 



3-60 



15-42 



6-12 



26-21 



0-60 



2-56 



0-33 



1-41 



1-10 



474 



4-09 



17-50 



10-52 



45-07 



100-00 



10000 



536 the stinging property of the giant nettle-tree, 



Summary of the Systematic Analysis. 



Fresh juicy leaves contain : — 



Water removed by drying at ordinary temp., 76-65% 

 Air-dried residue ... ... ... ... 23-35 



Moisture by air drying 



,, and vol. acids at 110° 

 Inorganic matter =ash 

 Extracted by solvents 



Petroleum spirit 



Ether 



Alcohol (absolute) 

 Water 



Cellulose, lignin (by difference) 



The following considerations will show the most probable mode- 

 of combination of the formic and acetic acids with the metals as 

 found in the analysis of the ash. 



Formates and acetates when heated are converted into carbon- 

 ates, and therefore exist in the ash as such. The portion soluble 

 in water contains 3-13 % of alkali carbonate, equivalent to K, 

 0-065% on the fresh leaves. By apportioning the acid having 

 the higher dissociation constant to the strongest base we find 

 that the whole of the combined formic acid requires 0'038 K, 

 leaving the rest of the K, 0*027, in combination with part of the 

 acetic acid, 0-041. The remaining 0-309 of acetic acid is then, 

 given to Ca, the metal next in order of avidity. We may now 

 state the results in their final form as follows : — 



( Free formic acid ... 

 Free acids -! Free acetic acid 



(^ Higher members of acetic series 



| Potassium formate 

 Salts ... -J Potassium acetate 



( Calcium acetate 



On fresh 



On air-dried 



leaves. 



leaves. 



0-002% 



Nil. 



0-177 



Nil. 



Traces 



Nil. 



0-082 



0-351 



0-067 



0-287 



0-406 



1-739 



0-734% 2-377%. 



