The Wohurn Pof-CAilture Experiments, 1910-11-12. 319 



per cent., and '001 per cent, lithium. As befoi'e, the experi- 

 ments were in duplicate, the salts mixed with the whole soil 

 in a pot, and twelve seeds per pot sown November 21, 1911, 

 subsequently reduced to six growing plants per pot. There 

 were, accordingly, two pots with lithium phosphate containing 

 •003 per cent, lithium, two with '002 per cent., and two with 

 •001 per cent., and corresponding pots with lithium nitrate, 

 and with lithium carbonate. The first observations, as regards 

 the action of the respective salts on the incubation of the plant, 

 were very interesting, and woukl seem to go far in the direction 

 of showing that tlie influences which determine the ultimate 

 yield are mainly those which are exercised at the time of 

 germination rather than those that are active at a later stage 

 in the plant's history. 



It was noticed, first, that, as regards lithium phosphate, the 

 higher amount ('003 per cent.), though it did not injure the 

 germination, prolonged the period of incubation of the seed by 

 quite three days ; with lithium nitrate ("003 per cent.) there 

 was an even greater retardation, but with lithium carbonate 

 there was practically no change as compared with the control 

 plants (untreated). With the lower amounts, however, of 

 lithium — whether used as phosphate or as nitrate — there was 

 no increase in the incubation period of the plant, and the shoots 

 appeared quite as readily as with the control plants. 



As the plants grew on, it was next observed that where the 

 heavier applications ("003 per cent.) had been given the plants 

 began to show a yellowishness of the leaf, and to fall away. 

 On the other hand the smallest addition of lithium (-001 per 

 cent.) seemed to give the most satisfactory looking crops, 

 together with a darkening of the foliage, as if chlorophyll 

 activity and starch assimilation had gone on more favourably. 



The relative appearances are shown : (1) In Plate 3, where 

 {a), (i), (c), {d), represent respectively no treatment and lithium 

 phosphate in increasing quantities ; (2) In Plate 5, where the 

 action of lithium nitrate is shown ; (3) Plate 7, where that of 

 lithium carbonate is exemplified. The respective appearances 

 presented are very fairly brought out in the weights obtained 

 at harvest, the comparative results being as follows : — 



