316 SULPHURETTED HYDROGEN. [BOOK n. 



solution had a most nauseous, disgusting smell, and contained 

 of course a large quantity of sulphuretted hydrogen. The 

 plants under experiment were selected from many, and were 

 of the same age and size, and as far as possible of the same 

 healthy state of growth. Some were watered with common 

 water, others with a dilute solution of hydrosulphuret of 

 ammonia. At first only a few drops of the solution were 

 given ; but finding that this produced little or no effect, the 

 dose was increased, and as much as half an ounce a day, and 

 sometimes even more, was given to each plant. It was found 

 that those thus treated became stronger and sturdier ; their 

 leaves were of a bright deep green ; the space between the 

 nodes, or the distance from leaf to leaf, was shorter, and the 

 stems were stronger, and the whole plant more flourishing 

 than those watered in the ordinary way, although all other 

 circumstances were alike, and care was taken to place all 

 under the same condition, by exposing them equally to air 

 and light, and giving them the same quantity of water every 

 day. Plants in a languid state from over-doses of nitrate of 

 potash, or soda, or other saline manures, if not too much injured 

 by their previous treatment, appeared to recover more rapidly 

 when watered with the solution of hydrosulphuret of ammonia 

 than when merely treated with common water. In some of 

 these latter cases a much stronger solution was employed 

 than that already mentioned, containing two drachms of the 

 saturated solution of hydrosulphuret of ammonia in fifty of 

 water, and of this eight drachms were given daily. For some 

 time after thus watering the plants, the earth retained a 

 strong smell of sulphuretted hydrogen, and the water which 

 drained through, when tested by a salt of lead, evidently 

 contained a large quantity of that gas." 



This is only what was to be expected from the abundance 

 of this gas in nature, from the rankness of vegetation when 

 it is extricated copiously, as in the vicinity of privies, and 

 from the fact of its being given off incessantly by putrid 

 substances, and that it is most abundant in the most active 

 of all manures. The error that seems to have been committed 

 by the chemists who investigated its action, appears to have 

 arisen from their submitting plants to too large a dose of it. 



