166 DErARTMENT OF AGRICULTURE. 



and the chaibou or aiitlirax of many parts of the Avorld. The one passes 

 from eatth^ to catth'; the other is deadly to men, horses, dogs, pigs, and 

 other warm-blooded animals. 



It is evident that principles which exert such a variety of definite in- 

 flu(^nces must have fundamental characters to distinguish them — that 

 the virus of small-pox may some day be capable of distinction in its virus 

 form from the virus of rinderpest or the lung plague. 



As far back as 1S49, Mr. L. E. Plasse a veterinary surgeon at Xiort, 

 Deux Sevres, in France, published a work, illustrated by tables and a 

 map, in which he announced the discovery of the causes of epizootics and 

 epidemics, with the distinguishing features of two forms of charbou or 

 anthrax, the one gangrenous and the other virulent.* It is a common error, 

 due mainly to the undetermined meaning of a much used medical term, 

 to regard epidemics and epizootics as typhoid fevers. Thus confounding 

 many maladies, M. Plasse, in vainglorious terms which characterize his 

 whole volume of near 500 pages, says: "JVy/ reconnu que les Jievrcs 

 typJtoides, qui, cliez Ics animaux, sont semhlahles a celle de Vhomme, 

 dependent toujours d'une seide et menie eause: des champignons micros- 

 copiques introduits dans Veconomie animale par les aliments ; et je demon- 

 trerai clairement que Unites les causes qui ont etc indiquees ne sont quHn- 

 directes et determinantes ; qu^elles sont le resultat de Verreur; et que la 

 veritable cause est une et invariable:^ M. Plasse was by uo means the 

 first to point to the lower forms of vegetable life as causes of disease in 

 men and animals; but it would be an unprofitable task to enlarge on the 

 earlier hints in this great field of error and of mystery. Plasse has the 

 credit of first publishing a comprehensive volume on the subject; and in 

 his succinct expose of the work before us, an expose which he read 

 before the Institute of France on the 9th of October, 1848, he says : 

 " I have had to substitute the general denomination of cryptogamy for 

 the various expressions applied to the diseases called typhoid, and I have 

 recognized four states of the cryptogamic maladies. 



" First state, cryptogamic incuhation. The toxic principle here may 

 sojourn in the animal economy during a greater or less length of time, 

 without causing marked functional disturbance; the disease will never- 

 theless be recognized by certain general symptoms. 



" Second state, cryptogamiG elimination. This is the discharge of the 

 poisonous principle from the animal economy, without apparent func- 

 tional trouble, whether by the excretions, the embryo in abortion, or the 

 sucking animal. 



" Third state, external cryptogamy. The morbid principle is eliminated 

 without apparent disturbance, and is fixed in a more or less apparent 

 manner on the surface of the skin, or in certain cavities which have exter- 

 nal openings. In this category are included glanders, farcy scrofula, 

 lupus, canker of horses' feet, (crapaud,) elephantiasis, tinea, lepra, &c. 



* Ddcouverte lies causes lies fipizooties et des 1^4>i»loiiii(s ; Causes ct distiuctiou de 

 deux genres.dc Cliurl><)ii. Ac. Par L. E. Plasse. I'oitiers, 1^49. 



