By Mr. Robert Fortune. 



519 



From this table it will be seen that the plant in No. 1, where 

 the mercury was, became visibly affected on the 5th day, that in 

 two days afterwards some weeds which vegetated in the soil also 

 looked sickly, and that it gradually became worse up to the 

 15th, when it had lost all its leaves and was removed from under 

 this hand-glass, and placed under No. 4, which contained the weak 

 muriatic acid. This change of circumstances had a marked effect 

 upon the sickly plant which now began gradually to recover, and 

 on the 30th of May — about six weeks after its removal — it was 

 perfectly healthy. 



At the time that the last plant was removed from No. 1, namely, 

 on the 15th of April, another healthy one was introduced, which 

 suffered in the same manner, and lost all its leaves in nearly the 

 same space of time. 



In No. 2, where the corrosive sublimate and moistened sawdust 

 were, no bad effects were visible until the 12th day, but at that 

 time the leaves began to curl and look unhealthy, turning yellow 

 and finally dropping off, so that on the 15th of May it was removed 

 with scarcely a leaf remaining. Another healthy plant was then 

 placed in the same circumstances, and suffered in the same manner, 

 though not so rapidly as the first. 



No. 3, had no preparation of any kind under the hand-glass, and 

 the plant here continued to grow throughout the whole time of the 

 experiment without suffering in any way further than getting drawn 

 up and having its top injured by the pressure of the hand-glass. 



No. 4. The diluted muriatic acid had a most beneficial effect 

 upon the balsam in this hand-glass, it grew more luxuriantly than 

 any of the others, and the weeds in the pot vegetated and flourished 

 in a very remarkable manner. Further, as before remarked,— 

 the sickly leafless plant brought here from No. 1, gradually reco- 

 vered and was soon in a high state of health. 



The plants in Nos. 5 and 6, where the dry calomel and dry 

 corrosive sublimate were, did not seem to be at all affected until 



