FUNCTION.] SULPHURETTED HYDROGEN. 315 



injured in colour, were hanging down perpendicularly from 

 the leafstalks, and quite flaccid ; and, though the plant was 

 then removed into the open air, the stem itself soon began 

 also to droop and bend, and the whole plant speedily fell over 

 and died. When the effects of a large quantity, such as six 

 inches in sixty times their volume, were carefully watched, it 

 was remarked that the drooping began in ten hours, at once 

 from the leafstalks ; and the leaves themselves, except that 

 they were flaccid, did not look unhealthy. Not one plant 

 recovered, any of whose leaves had drooped before it was 

 removed into the air. (Turner and Christison.) 



The general opinion respecting the action of this gas has 

 been unfavourable. It evidently acts on plants as a veno- 

 mous vapour, says M. De Candolle (Phys. 1363) ; it destroys 

 plants when mixed with the air in small doses, and is chiefly 

 inhaled at night, adds the same author in another place 

 (p. 1372), judging from some experiments of the Genevese 

 chemist Macaire. Liebig broadly states that one of the 

 chemical forms in which this agent exists is a deadly poison ; 

 and acting, it may be presumed, upon such assertions, the 

 proprietors of gas-works have been exposed to actions from 

 their neighbours to recover compensation for some supposed 

 injury done to their gardens. One would imagine that state- 

 ments in which great authorities thus concur must be well 

 founded. Mr. Solly's experiments, however, by no means 

 confirm them. On the contrary, it would seem that sulphu- 

 retted hydrogen gas acts decidedly in a beneficial manner. 

 He says " I made use of the hydrosulphuret of ammonia, 

 the very compound described by Liebig as being a ' deadly 

 poison ;' but in place of killing plants, I found that in small 

 quantity it produced decidedly beneficial effects ; in some cases 

 when it was applied to plants, in an unhealthy state from the 

 action of other substances, it had the effect of invigorating 

 them, and of restoring their leaves to a healthy, green, and 

 crisp condition. The plants with which these effects were 

 best observed were the garden Lettuce and the common 

 Windsor Bean. The solution of the hydrosulphuret of am- 

 monia employed was prepared by mixing a saturated solution 

 of the compound with fifty times its bulk of water : such a 



