51 



Matter. The following table gives the loss, in a considerable period, of 

 both available and total (calculated on the non-sandy part of the soil) 

 Phosphoric Acid, the former in parts per 100,000, the latter in 

 percentages. 



CAUSE OF RELATION OF PHOSPHORIC ACID TO QUALITY. 



But why does Phosphoric Acid play such a preponderating 

 part in the production of high quality teas ? Researches pursued 

 in connection with other plants give us the clue to the reason. In 

 all cases wherever the production of new tissue in plants is most 

 active, there Phosphoric Acid plays a principal part. No albumens, 

 no cells, and hence no tissue can be formed in its absence. Now 

 as those parts of the plant used in tea manufacture are those in 

 which the production of new cells is extremely vigorous and 

 energetic, so is this constituent of more importance for the perfect 

 production of the crop than with ordinary agricultural products. 

 There is another reason also. It has recently been shown that 

 the acidity of plant juices depends on the amount of Phosphoric 

 Acid in the soil. Now the younger leaves and hence those which 

 make the best tea are more acid than the older ones, and so one 

 is, I think, entitled to assume that a certain proportion of acidity 

 is necessary in the leaf for making the best tea, and this is rendered 

 more certain by the presence of much Phosphoric Acid in the soil. 

 The following table shows the acidity, and also the percentage of 

 Phosphoric Acid calculated on the dry matter, in the unopened 

 bud, in the first two leaves and in the stalk of a flushing shoot taken 

 from a hybrid bush in Darjeeling in August 1901, and it will be 



