INVARIABLE QUANTITY OF ALKALINE BASES. HI 



ferent plants, and yet even here the quantity of 

 oxygen in the bases of both was the same. 



100 parts of the ashes of firwood from Allevard 

 contained, according to Berthier, (Ann. de Chim. et 

 de Phys. t. xxxii. p. 248,) 



Potash and Soda 16*8 in which 3-42 parts must be oxygen. 

 Lime . 29-5 " 8-20 " " 



Magnesia . 3-2 « 1.20 " " 



49-5 12-82 



Only part of the potash and soda in these ashes 

 was in combination with organic acids ; the remain- 

 der was in the form of sulphates, phosphates, and 

 chlorides. One hundred parts of the ashes contain 

 3*1 sulphuric acid, 4*2 phosphoric acid, and 0*3 hy- 

 drochloric acid, which together neutralize a quantity 

 of base containing 1-20 oxygen. This number there- 

 fore must be subtracted from 12-82. The remainder 

 11*62 indicates the quantity of oxygen in the alka- 

 line bases, combined with organic acids in the fir- 

 wood of Allevard. 



The firwood of Norway contained in 100 parts,"* — 



Potash . 14-1 of which 2-4 parts would be oxygen. 



Soda . 20-7 « 5-3 " " 



Lime . 12-3 " 3-45 " « 



Magnesia 4-35 " 169 '' " 



51-45 1284 



And if the quantity of oxygen of the bases in com- 

 bination with sulphuric and phosphoric acid, viz. 

 1-37, be again subtracted from 12*84, 11*47 parts 

 remain as the amount of oxygen contained in the 

 bases which were in combination with organic acids. 

 These remarkable approximations cannot be acci- 

 dental ; and if further examinations confirm them 

 in other kinds of plants, no other explanation than 

 that already given can be adopted. 



* This calculation is exact only in the case where the quantity of 

 ashes is equal in weight for a given quantity of wood ; the difference 

 cannot, however, be admitted to be so great as to change sensibly the 

 above proportions. Berthier has not mentioned the proportion of ashes 

 contained in the wood. 



