33S 



PIlOrUEDINOS OK TMU 



bivn said aiul writtiMi on the evil ctlVcts produced by muriatic 

 ui itl ijas on plants, attention having been very fre(juently drawn 

 lo the subjec t in ej)nse(iuenco of lenjal pro('eedini::s being- institu- 

 ted at Newcastle, Liverpool and other places a<j;ainst alkali manu- 

 facturers, the muriatic acid evolved in their factories being- con- 

 sidered a nuisance, and suj)posed to ])roduce very bad eflects on 

 the gardens and fields in (heir neighbourhood. Notwithstjuiding 

 all this, no direct and conclusive experiments have been made, and 

 the general impressi(Ui is, that muriatic acid is a most poisonous 

 substance, even when applied in very small quantity to growing 

 plants. In the experiments on Hydrangeas which I have men- 

 tioned, I was surprised to find how very large a (quantity of this 

 acid the plants were able to take up, and that so far from produc- 

 ing bad effects they flourished under its influence. The greatest 

 quantity which I gave was from one-fifth to one-fourth of a 

 drachm of strong acid to the plant i)er day, of course dissolved in 

 a larger quantity of water, but still so strong as to be about as 

 sour to the taste as common vinegar. 



The other fact observed in these experiments was a great ap- 

 parent diminution in the rate of evaporation from plants watered 

 with the dilute acid. Thus when two Hydrangeas, the one 

 "N^atered with acid, the other with carbonate of soda, were placed 

 under the same circumstances, and watered with three ounces of 

 ■water each, the one watered with the alcaline solution began to 

 fade and seemed parched up by heat in the middle of the day, 

 -whilst the other remained crisp and fre^h looking ; subsequently 

 it received five ounces of water daily, but even this did not seem 

 sufficient, and seven ounces of water were found necessary to 

 keep it in a condition similar to the other which was watered with 

 three ounces, but under the influence of the muriatic acid. It 

 might at first ba supposed that this effect was principally due to 

 the action of the carbonate of soda, but by comparing the plants 

 with others similarly situated, there appeared little doubt that 

 the rate of evaporation was diminished in that under the influence 

 of the acid, and not that it was increased in the one watered with 

 the alcaline solution. 



The results which these experiments would lead to are curious 

 and well worthy of being carried out. With regard to the effects 

 of the acid on plants I may mention that experiments made at 

 the Horticultural Gardens by Mr. Fortune, which are described in 

 the last part of the Society's Transactions, lead to conclusions 

 perfectly in accordance with those I had arrived at. He was de- 

 sirous of ascertaining the action which Kyarised wood had on 

 plants, in situations where they were exposed to the action of 

 vapours arising from mercury, corrosive sublimate, and muriatic 



