190 THE FLORIST AND 
REMEDY AGAINST MILDEW. 
A question was asked some time since by one of our correspondents, 
whether sulphuret of potash* had ever been employed as a remedy against 
Mildew ? We cannot say whether it has been so applied in this country, 
but it has been used in France successfully, and if an acid be added, a fine 
preciptate of sulphur is deposited from the aqueous solution upon the leaves 
of the Vine or Hop, in a manner which would not be effected by any dred- 
ging.f It is, in fact, when properly diluted, precisely what is used very 
frequently for baths in certain cutaneous disorders. In all such applica- 
tions the main question is, how does the sulphur act ? This is evidently a 
point of great importance, and from the insolubility of sulphur under 
ordinary circumstances, not very easy of explanation. 
We do not profess to be in a condition to answer this satisfactorily, but 
the observations we have to offer may induce some one to attend a little 
more closely to the matter. Sulphur has evidently a very prejudicial effect 
on fungi, as it has indeed on all organic beings if exposed to it in a pro- 
per form, and in a suflBcient degree of concentration. The use of sulphur 
in cutaneous disorders, whether arising from insects or vegetable parasites ; 
the effect of hypo-sulphite of soda on the curious vegetable products known 
by the name of Sarcina, from its resemblance to little corded bales, which 
is so common in cancerous affections of the human stomach ; and the de- 
structive power which it has over parasitic moulds, are all evidences of this 
fact. One particular instance may perhaps afford a clue to its action over 
the latter. It is well ^known that if a bundle of brimstone matches be 
burnt in a barrel, the fermentation of wine when placed in that barrel will 
be arrested. Now, the fumes of brimstone consist of sulphurous acid, and 
as the whole body of the wine placed in the cask is affected, the quantity 
of the acid which is capable of arresting the growth of the yeast fungus, 
must be almost infinitesimal. Now, if the leaves of plants infested with 
mould are dusted with sulphur, though the sulphur is insoluble in water 
and may be exposed to ordinary air for a long time without change, it is 
very possible that the oxygen just separated from the foliage by the action 
of light effecting the decomposition of carbonic acid, or arising from other 
* We suppose by sulphuret of potash, or more properly sulphuret of potassium, is meant 
what is known by chemists, under the name of liver of sulphur. This is not a definite sub- 
stance, but consists of tersulphuret of potassium, hyposulphite of potash, and sulphuret of 
potassium. * 
J Sulphuretted hydrogen is erolved at the same time. 
