no 



I--lUi»ill(H'l'i;i{ lil.KillT OF srciAK-CANK 



Fig. 27 — Maj) of Cedar Hill estate shewing the distribution of blight in 1900, 

 1912 and 1919 in relation to soil. 



In 1917 a few spots of damage appeared in farmer's canes near this 

 estate on black soils, but this is the only case where the Manager had 

 seen damage on these soils. 



Many other examples will be found above (p. 105) in connection with 

 the influence of the contour of the ground, where it is shown that the 

 type of the soil is of greater importance and overshadows any small 

 influence that may be due to situation. 



In 1919 a number of damaged fields on Hermitage and Golconda 

 estates were observed to be roughly in a sti'aight line running East and 

 West. This is the direction of the geological strike in this district and 

 when the positions were shown to a local geologist he stated that the 

 damaged fields coi-responded very closely with the outcrop of a certain 

 type of clay as indicated by his geological maps. 



Chemical Composition of Soils. 



Carmody in 1909 (A) published an analj'sis of a soil at Cai-oni 

 strongly affected by blight and noted that the percentage of magnesia 

 exceeded that of lime. A. Urich in 1909 gives details of another analysis 

 of a soil from Caroni in which he also found a higher percentage of 

 magnesium than of lime, but came to the conclusion that there was 

 nothing in the composition of the soil to explain the prevalence of blight 

 "unless it be the extraordinary impermeability." 



In 1918 I made an attempt to find the chemical differences between 

 the damaged and undamaged soils in the Naparimas. Messrs. Tennants 

 were good enough to allow their Chemist to analyse the soils of ten 



