158 History 0/ Anwial Plagues. 



A.D. 1689. In mankind, ^spotted fever, small-pox, and 

 others; then followed murrahi of sheep.' ^ 



A.D. 1690. Ramazzhii writes: 'For the first four or five 

 years preceding this, the whole of Italy had experienced uncom- 

 monly dry weather, during which time all the crops were most 

 abundant, and it was imagined that there would be universal 

 I good health ; for it is commonly and correctly believed that 

 I everything is more healthy in dry weather. In the year preced- 

 1 ing this, however (1689), about the time of the equinox, heavy 

 rains fell, which continuing during the whole spring of the year, 

 produced an unfavourable season. The summer continued for 

 the most part rainy. About the time of the summer solstice 

 signs of rust ^ {riibigo) in the wheat began to be observed, which 



^ T. Forster. Loc. cit. 



2 The rust of plants, the Epj;(Tt/3j/ of the Greeks, 7-obigo of the Romans, who 

 had their fiction regarding the god Robigus, and their Robigalia or Robigalia festa 

 in his honour to avert this destroyer, the rouille of the French, der rost of the Ger- 

 mans, and the rubigo of the botanist, has been known from the earliest times, but 

 it may well be doubted' if, until modern days, many diseases of plants have not 

 been included in this term. It is only within a few years that the study of the 

 various microscopical fungi has revealed the true nature of the enphytozics or epi- 

 phytozics to which they give rise. Unger was of opinion that the causes which 

 led to their appearance in the plant are to be foimd in the ground, the electricity 

 I of the atmosphere, humidity, and the absence of light. Theophrastus thought 

 rust was due to the rays of the full moon, and Diogenes Laertius relates how the 

 philosopher Empedocles preserved tlie crops of Agrigentum against tlie rust by 

 hanging up the skins of animals between them and the north wind. The physi- 

 cians of the si.xteenth century imagined its appearance was owing to a malignant 

 dew, and in the south of France at the present day the agriculturists are so per- 

 suaded that tlie rust of wheat is due to a fog or mist, that they term it the maladic 

 brouillard. The generative faculty and contagious character of the several fungi 

 are not yet sufficiently known to be definitely pronounced upon. Mr Cook, in his 

 excellent little work on ' Microscopi Fungi,' says of them : 'Unfortunately, this 

 group of fungi contains species but too well known for their ravages amongst gram- 

 inaceous plants, especially the cereals. "Corn rust," as it is generally called, has a 

 reputation little better tlian mildew, and it really deserves no better, for it is only 

 another form of that pest of the farm, from the mycelium of which the corn-mildew 

 is at length developed. There are two species very closely allied (doubtless only 

 forms of the same species with different spores) which attack the leaves and culms 

 of growing corn, and bursting through the cuticle, give a peculiar rusty appearance 

 to the plant. One of these corn-rusts is botanically termed Trichobasis rnbigo-vfra, 

 or the "true rust Trichobasis," the latter, which is the generic name, being a com- 

 pound of two Greek words (t/irix, a hair, and basis, a foundation), on account of 

 the spores being at first furnished at their base witli a short, thread-like peduncle, 

 which at length falls away. The other corn-rust is Trichobasis Ii7!eans, or " line-like 

 Trichobasis," htcau?,e the sori or pustules are linear, or lengthened out like a line ; 



