FUNGI, 5* 



matter. It is tins property Nvliicli renders one or two species, 

 known under the common name of dry rot, such a dreadful 

 plague in ships and buildings. The disease doubtless originates 

 on some unsound portion of the wood, but, once established, it 

 spreads with wonderful rapidity and decomposes tlie sound 

 wood beneath it, by absorbing its nutritive matter. Tiie remedy 

 is not difficult, where it is practicable to guard against the 

 concurrence of circumstances favourable to its progress ; but in 

 many instances this is impossible. Various schemes have been 

 proposed for its general prevention, but unsuccessfully, until 

 JNfr. Kyan impregnated the wood witii corrosive sublimate, a 

 well known enemy to vegetable life, which by combining with 

 the nutritive matter of the wood renders it unfit for the support 

 of vegetation, and as far as such short experience can testify, 

 completely proved its efficacy. White of ^^^ might probably 

 be used with advantage on a small scale, as it seems, equally 

 with corrosive sublimate, to prevent the growth of fungi ; 

 indeed it is sometimes employed by liouse-kecpers for the pre- 

 vention of mould by simply covering the articles to be preserved 

 with paper steeped in it. In herbaria and cabinets, mouldiness 

 may be kept away by the use of essential oils, or Russia leather. 



Fungi are very destructive to corn, in the form q^ Blight, 

 3Iildeir, Bunt, &c., doing injury not only by a diminution of the 

 rjuantity but also of the nutritive matter, and as in tlie case of 

 Bunt, by communicating to the corn an offensive taste and 

 smell. Tlie growth of these parasites depends so much upon 

 accidental circumstances, that it is impossible for the most 

 experienced cultivators to guard against them altogether, but 

 the evil is greatly lessened by careful choice of seed, by steep- 

 ing it in solutions of different substances, which destroy tlie 

 vegetative power of the spori'lia of those parasites, and by a 

 judicious change of cropping, in the land subject to them. It 

 appears that the reproductive contents of the sporidia arc 

 absorbed together with tlie water, containing the nutritive 

 matter of the soil by the roots. At least it is certain that corn, 

 sown in soil, which iias been purposely mixed with (ho sporidia, 

 is infested with the fimgi to which those sporidia belong; and 

 this lias been proved rdso with regard to one of the eutophytal 

 ])arasites to which Koses are subject. Most plant*^ are preyed 

 upon by their peculiar para-^it^'s ; Pear-trees, for instance, are 

 sometimes much irijured bv .IJridiuui cancellatuni, and young 

 trees planted in their neighbourhood are observed to suffer. 



Tlie roots of certain plants, ns StifJ'ron- Crocus, Lucernr^ 

 Convolvulus Batatas, Scz, are frequently exhausted by sub- 

 terranean fungi. In the case of Saffron, tlie only remedy is* to 

 insulate tlie infected plot by a deep trench, which should seem 

 to be a striking proof that these plants are really increased by 

 seed. 



