PREPARING SEED BEFORE SOWING. 187 



used, under which conditions the chlorine appears to 

 oxidize the sulphurous acid, with formation of sul- 

 phuric acid and hydrochloric acid, which, in turn, would 

 attack the vegetable fiber unless great precautions be 

 taken. It has been shown that sodic carbonate and 

 sodic nitrate, or even sodic sulphate, in one-eighth 

 solution, are not desirable stimulants. 



Boettger has declared that germination is consid- 

 erably hastened by steeping the seed in weak solutions 

 of soda, potassa or ammonia; in fact, two degrees Be 

 solution of ammonia sulphate resulted in 71 per cent, of 

 seed germinating in a week; possibly the ammonia 

 from barnyard manure has a like effect. On the other 

 hand, ammonia carbonate in one-eighth solution 

 destroys completely the vitality of the seed; with a solu- 

 tion of II per cent, chloride of sodium the stimulation 

 was no greater than it was with distilled water. Alum 

 appears to be favorable to germination. Pagnoul 

 experimented with the following substances, all con- 

 sidered separately: Phenic acid, 0.2 per cent.; potas- 

 sic arsenate, i per cent.; zinc sulphate, 2 per cent.; 

 sulphate of copper, 2 per cent.; also with magnesia sul- 

 phate, 5 per cent, in 100 parts water; with the last the 

 best results were obtained, the steeping lastitlg only 

 five minutes. 



With 5ppr cent, olilorai.e of ammonia. 



77 out of 100 germinate in 15 days. 



39 per gram" " " " 



Saltpeter is highly recommended by some experts, 

 as 85 per cent, of seed germinated in a week. Of the 

 metallic salts which appear to influence germination, 

 white sand, if mixed with lo per cent, ferric-sulphate, 

 will completely destroy the vitality of the seed; eveii 

 2 per cent, had an important influence, which disap- 

 pears entirely when only one-fifth per cent, is used. 



We would say, respecting these chemicals, that, 

 even admitting that certain advantages are to be 

 derived, they are hardly within easy reach of the aver- 



