STATE HORTICULTURAL SOCIETY. 53 



generation. There are no trees that ever existed, not even those in Paradise, that 

 were entirely free from rot. For whenever worn out tissue, whether root, limb, or bark 

 was thrown off, there was dead matter, and consequently the normal condition 

 of dead matter, rot. Yet, notwithstanding this, trees have been healthy, and 

 have borne healthy fruit. I rather think culture may have wrought constitutional 

 enfeeblement, similar to that we know has been wrought in animals and even in man, 

 that they cannot withstand the vicissitudes of climate as in their wild state. They 

 moreover are exotics, and their transfer from one extreme to another of such climatic 

 and meteorological conditions, may be more than their constitutions may have been 

 able to bear. It may have produced enfeeblement, and the condition of enfeeblement 

 is liability to disease. 



It has already been stated that fungi will seize and destroy dead matter, whether it 

 be the detergement of trees or the exuviae of animals. But it is likewise true that 

 some fungi will seize upou and not destroy living tissue, in which by some means, 

 vitality has been enfeebled. It is now admitted that intermittent and inflammatory 

 fevers are accompanied, and some suppose, caused by fungoid development. If a per- 

 son has had the ague once, a walk in the dew before breakfast, on a chilly morning, will 

 bring on a return of the paroxysm ; why, because the vital action is lowered by the 

 6uddcn chill brought on by the dew. Now, how is it with the rot in grapes?, My 

 observations are, that the grape rot, especially in the Catawba, invariably follow cold, 

 chilly weather in early summer. It is therefore evident that whatever impairing or 

 lowering even temporarily, vitality in plants or animals, induces to disease, or favors 

 fungoid development on living tissue. 



There are probably fungi that will attack plants which have unimpaired vitality, as 

 the small-pox fungus will man, or perhaps the Texas cattle disease. The pear blight we 

 know can be communicated by inoculation ; and Dr. Hull told us last night that he had 

 done so with the yellows in peaches. 



These facts show that there is an analogy between the diseases of plants and those of 

 mankind. May not the diseases of both be analogous throughout? And may not viti- 

 ated air play an important part in plant disease ? There has been much speculation on 

 the subject of miasmatic atmosphere, by scientific men. Speculation without facts is 

 merely guessing, and guessing can never establish anything upon the immovable basis of 

 truth. It may project a hypothesis, but cannot advance even to a theory, much less to a 

 scientific demonstration of a physical law. Investigation and experiment may elicit 

 facts, which may give rise to an hypothesis, and a series of facts may advance the hypo- 

 thesis to a theory, but it takes a whole cycle of facts all pointing to a common centre, to 

 advance a theory to a scientific truth. That all endemic and many epidemic diseases 

 originate in some atmospheric derangement is an unquestionable fact; but chemical 

 science has been baffled in all its attempts to determine the difference between a mias- 

 matic and a pure atmosphere. Since chemistry failed to answer the question, what is a 

 vitiated atmosphere, men have sought the answer in another direction ; and so have pro- 

 jected the hypothesis, that since chemistry cannot And any admixture of deleterious gas 

 in the atmosphere, therefore, ti rst , there is none ; and secondly, the Contamination must 

 consist of an almost infinite number of invisibly small Bporangta of fungi that grow in, 

 and about marshes, stagnant pools, or wherever vegetable or animal matter is decaying. 

 The now admitted (act, that many diseases, especially inflammatory fevers, are accom- 

 panied by fungi in the system of the patient, seemed to them to prove this hypothesis. 



