Before considering the compounds of sulphur, which hold so high a rank among the antizymotics, it may not be out of place to treat of that element uncombined, in its relation to the present subject. Though the influence of sulphur over fermentation has not, so far as I know, been fully tested, yet there is no doubt that it is extremely hostile to the lower organisms, both animal and vegetable. The certainty with which it cures scabies is an evidence of its power of destroying the itch-insect; and its efficiency in the prevention or cure of the disease which has of late years been so injurious to the vine, in the wine-growing countries of Europe, arises from a similar action on the microscopic fungus on which that disease depends. it is extremely probable that it is equally capable of destroying the vital principle of different ferments; but the greater efficiency and facility of application of those of its compounds which are now to engage our attention, render a recourse to it, under ordinary circumstances, unnecessary.*

* There is an application of sulphur which has often suggested itself to me, as promising very beneficial results in our agriculture, could it be made with (suffiicient economy. I refer to the prevention of the so-called red rust, which is so destructive to our wheat crop in certain seasons. This disease of the wheat is probably owing to a minute fungus, which attacks the surface of the stalk when the grain is forming, and so far disorganizes it as to prevent the ascent of nutriment to the young grain, the development of which is thus prevented. Now if sulphur should prove as fatal to this cryptogam as to that of the vine, it might possibly, if duly applied, save the crop. The question of its usefulness, however, is one which can only be practically solved, whether in regard to the point of efficiency or economy. [Note to the third edition.)