224 TRANSACTIONS OF ROYAL SCOTTISH ARBORICULTURAL SOCIKTY. 



indeed all the mineral elements essential to the life of plants. 

 He also concluded that these various inorganic salts were 

 soluble, and in a condition to be directly assimilated by plants. 

 Grandeau next proved that the amount of mineral matter present 

 in the ''black matter" may be taken as an inde.x of the fertility 

 of a soil. 



The following figures from one of his {)apers may be taken 

 as an illustration. 300 grammes soil contain : — 



Soil from Soil from Peaty Soil from 



Russia. Lorraine. Nancy. 



Organic ^Matter . yio i t -oo 35-99 grams. 



" Black Matter" . 4-20 0-94 roo ,, 



Amount of ash in the \ 



"Black Matter" from V 2- 16 0-12 0-02 ,, 



100 grammes of soil ' 



The proportion of "black matter" cannot be used as an 

 index of the fertility, for the peaty soil from Nancy, which is 

 quite barren, contains as much as the fertile soil from Lorraine. 



Grandeau therefore concluded that the higher the percentage 

 of ash in the "black matter" the more fertile the soil, and he 

 gives the following figures showing the percentages of ash in 

 the '"black matter" from various classes of soil. 



\'ery I'erlile Soil o( I'air Barren 

 Soil. j-'ertililv. Soil. 



Percentage of ash in ] ,, 



"Black Matter" ) 5^'^° '''^° 



He further states, with regard to the phosphoric acid, that 

 fertility depends not so much on the total amount of phosphoric 

 acid present as on that part of it which is in combination with 

 the "black matter." These new ideas as to the fertility of soils 

 were first published by Grandeau in 1878, in the Annales de la 

 slation Agronomiqiie de VEsf. 



Many agricultural scientists in all countries have since that 

 time paid their tribute to the importance of Grandeau's 

 researches. 



[M. Grandeau was a professor at the I'rcnch Xationul Forest School, 

 Nancy. His monumental book on "Chemistry and Physiology applied to 

 Silviculture " (Per^'er-Levrault, Paris, 1878), was for long the standard work 

 on this important sul)ject, and the analyses recorded in it must muinlain for 

 all time its great value to students of forestry. — Hon. Ed.] 



