1878.] 



Supersaturated Saline Solutions. 



125 



oil in falling through the air, must have caught up particles of sodic 

 sulphate, and these, and not the oil, formed the true nucleus. 



To meet this objection, I took a portion of the same solution, con- 

 tained in a wide-necked flask, to the same spot in the open air of my 

 garden, and with a clean dropping- tube, just taken out of water, raised 

 a quantity of the supersaturated solution, and allowed it to fall through 

 the air drop by drop into the flask. This was done repeatedly, a south- 

 easterly wind blowing gently at the time, but the solution remained 

 unchanged. 



An old oil of lavender (marked "Mitcham") was active. It was 

 redistilled and treated as in the preceding case, with the same results. 



Methylated spirits of wine were inactive during a south wind, but 

 soon became active on being allowed to drop through the air in my 

 garden. Benzole became similarly active, but not quite so readily. 



An old paraffin oil (marked " Belmontine ") was active. Its distil- 

 late was inactive, but on adding to it a few drops of ozonised water, it 

 became active. 



A solution of sodic sulphate, to which some drops of oil of cajuput 

 had been added the day before, did not solidify, although the solution 

 had been repeatedly shaken in the flask. A few drops of ozonised 

 water were added, and the solution became solid on gently shaking 

 the flask. 



Oil of sweet almonds was inactive ; but on being dropped through 

 the outer air, it became active. About twenty old essential oils were 

 all powerfully active. 



A piece of apple, cut from the centre of the fruit, was inactive ; 

 several pieces, similarly cut and exposed to the air until they had be- 

 come brown, were active. 



Bits of sponge, which were described in my former paper as being 

 inactive, were found to be active during a northerly and north-easterly 

 wind. The same remark applies to charcoal. 



These experiments may suffice to show what is really the function 

 of the air with respect to nuclei, and to account for and bring into 

 harmony with a general principle a large amount of contradictory 

 evidence on the part of many observers, which, during three-quarters 

 of a century has disturbed this branch of physico-chemical science. 



Why the oils, &c, in their oxidised condition are nuclear, and in 

 their pure condition not, is a question which I am now endeavouring 

 to answer. 



