318 The Wohurn Pot-Culture Experiments, 1910-11-12. 



(•0025 per cent, lithium) the effect seemed to be one merely of 

 retarding germination, for whereas by January 28 the control 

 plots had ten or eleven of the twelve grains up, with lithium 

 phosphate there were only six, and with lithium nitrate only 

 five plants, though more appeared later on. But with all the 

 higher amounts of lithium — whether as phosphate or nitrate — 

 the germination was more and more affected as the salts were 

 in more concentrated form, and the plants never reached their 

 full number. More especially was this the case with lithium 

 nitrate, no plants coming up at all where the heavier appli- 

 cations were given. 



The appearances of the growing crops are shown in Plate 1 

 and Plate 4. It wall be seen, in Plate 1, that the only lithium 

 phosphate application equal to the "no treatment" (a) is that 

 of '0025 per cent. (&), and that (c) is almost an entire failure, 

 and (d) and (e) complete failures. Similarly, with Plate 4, 

 (rt) alone shows any increase over the untreated lot ((a) of 

 Plate 1), while (c) and (d) are quite blanks. 



On coming to thresh out and weigh the corn and straw the 

 following comparative results were obtained : — 



No treatment ...... 



Lithium phosphate — "0025 per cent, lithium 



„ -, '005 „ 



Lithium nitrate — "002.5 per cent, lithium 



„ ,• "005 



On comparing these results Avith those of 1910 it will be 

 seen that the two are closely alike as regards lithium phosphate 

 when used up to '002 or '0025 per cent, lithium, and show that 

 there is a slight stimulus up to this point. If, however, this 

 quantity be materially exceeded then there is injury to the 

 germinating seed, this being the more marked with the greater 

 concentration. 



As regards lithium nitrate, the results go to confirm to some 

 extent the results found in 1909 as to a marked stimulative 

 effect if •0025 per cent, of lithium be not exceeded ; also that 

 this action is more marked with the nitrate than with other 

 salts of lithium. If, however, this quantity be exceeded, the 

 effect is a toxic one, and more marked with the niti-ate than 

 with the phosphate. 



3. Lithium Phosphate, Lithium Nitrate^ and Lithium 

 Carbonate. 1912. 



On obtaining the results just set out, it was determined to 

 see whether quantities of lithium markedly below '003 per 

 cent, produced a stimulating effect. In addition to the phos- 

 phate and nitrate as before, lithium carbonate was now brought 

 in. The quantities used were the same in the case of each salt 

 and were fixed at supplying respectively ^003 per cent., ^002 



