12 



Rust. 



Vol. VI. 



collection, on wheat, rye and oats; and for 

 years, our most enlerprisinfr, industrious and 

 wealthy farmers, have adopted the system of 

 eeedinjT with prass on summer fallow, with 

 no apprehension of blight from such a prac- 

 tice. The isolated facta brought forward by 

 Col. S., may be explained by pathological 

 principles; yet nevertheless, are too few to 

 merit mucii notice, where they are borne 

 down by such a voluminous array of cases 

 as can be brought against them. By what 

 principle can the fact be explained — certain- 

 ly not by that of Col. S. — where rye and 

 wheat, standing in the same field, the latter 

 sown at the same time, or even later, and 

 manured with compost and lime, the former 

 with none ; the first blighted two weeks be- 

 fore the wheat; and at the time of blight on 

 the rye, not a vestige discoverable upon the 

 wheat, yet sporadic stalks of rye, standing 

 among the wheat, affected at the same time ? 

 Such was the case, and the rye had no grass 

 seed sown among it. Another field was sim- 

 ilarly injured ; but in this instance the rye 

 was sown on a fallow with grass seed, and 

 limed. The comparative yield was as three 

 to one, the maximum being in favour of the 

 rye that grass seed was sown among : the 

 timothy being, throughout the whole field, 

 very large. This is a case in point, and oc- 

 curred in my own farming. 



The idea of barberry causing blight, is too 

 ridiculous for notice; yet, as a popular error, 

 it has had, in its day, many zealous advocates 

 in England. 



The more plausible doctrine, and one which 

 has many supporters, is, that blight is a for- 

 tuitous production, occasioned by certain ac- 

 tions of heat, moisture, air, &c., upon plants 

 injured. That these agents caused blight by 

 a specific and peculiar action of themselves, 

 occurring at stated periods, without the inter- 

 vention of pre-existing sporules, is, to say 

 the least, problematical ; and does not give 

 a satisfactory nor philosophical reason why a 

 partiality is manifested toward wheat and 

 rye, whose functions and growth are so simi- 

 lar to other grains. If these agents are pos- 

 itively necessary, and rust be not an organ- 

 ized body, why should there not be other 

 diseased forms manifest, than that of blight, 

 whose appearance and characters in its form- 

 ation obey certain immutable laws? Erwot, 

 smut, mildew, &c., are diseased appearances 

 (using the common phraseology) of grain, 

 that show different symptoms. The charac- 

 ters of these several diseases are not the 

 eame, yet causes modified by the same cir- 

 cumstances, " et cacteris paribus," would in- 

 variably produce the same efl'ects. To talk 

 about rust, " which is but the outward sign 

 of the disease that preys on the vitals within," 

 is sheer verbosity : with as much plausibility 



and much more ingenuity, you might say it 

 is tuberculous, affecting the lungs of the 

 grain, for it first makes its appearance upon 

 the leaves, the acknowledged organ of oxy- 

 genization and carbonization. Perhaps it 

 may be caused by sudden transitions of heat 

 and cold — hence consumption; then these 

 outward signs are evidences of tuberculous 

 disease preying upon the vitals within — the 

 lungs. I do not wish to ridicule Mr. Gow- 

 en's opinion, for I entertain sentiments of 

 much respect for his views on other points, 

 by which he has enlightened the readers of 

 the Cabinet; but I must declaim against his 

 " stew-pans, or the shells that hold the milk ;" 

 " reservoirs or condensers that have ceased 

 to send off from the fountain that keeps bub- 

 bling up and flowing on," &c. Perhaps of 

 all the agents necessary for the formation of 

 rust, no one exercises such decided and es- 

 sential effects as caloric ; and by inference, 

 we may suppose it holds the balance of 

 power in vegetable physiology as it does in 

 the animal — for Broussais observes in one of 

 his propositions, •' Caloric, whatever may be 

 its nature, is the first and most important 

 of all stimulants, and if it cease to animate 

 the economy, others lose their influence over 

 it." Again : " Caloric brings into play the 

 unknown power which constructs the organs. 

 This power forms them from nutritive mate- 

 rials, and conducts the fluids into their inter- 

 stices." Here we have, by this agent alone, 

 organs endowed with vitality, with power to 

 fulfil the functions governing the economy, 

 and which of itself is sufficient to explain the 

 vital existence of fungi. 



Rust is of fungous growth, and exists to a 

 considerable extent. Under varying and pe- 

 culiar circumstances, fungus is found, but 

 possessing different characters, among decay- 

 ing masses of animal and vegetable manures, 

 on the bark or trunks of decayed trees, as 

 well as shrubs ; on grain, grasses, &c., &c. 

 When existing on living bodies, it is called 

 parasitical, and approaches in many of its 

 habits to the numerous tribes of lichens that 

 generally subsist upon air. The mildew 

 affecting the gooseberry, rose, &c., is a para- 

 sitical fungus, and so extensive is this tribe, 

 that at the present day botanists enumerate 

 between four and five thousand distinct spe- 

 cies. Its classification may be found in the 

 natural arrangement of Jussieu, called Uredo 

 linearis. Its generic name signifies blasting, 

 from the Latin uredo. 



The conclusions at which I have arrived, 

 concerning blight injuring our grain-fields, 

 are : First — that it is a parasitical fungus. 

 Second — that certain conditions of earth, 

 heat, moisture, &c., are absolutely necessary 

 for its development under any circumstances. 

 Third — that it is reproduced by sporules, and 



