TREATMENT OF SHEEP-POX. 37 



giving rise, in due time, to the symptoms characteristic of the 

 particular disease, and producing millions of particles like itself." 

 Monsieur Chauveau, of Lyons Veterinary School, has made 

 some very interesting experiments with the virus of several 

 contagious diseases. He found in the virus of Variola Ovina a 

 liquid and solid portion, the first being merely the medium, the 

 second the active principle, the latter alone being endowed with 

 virulent properties. He found that the character of the virulent 

 matter of smallpox in the human subject was, in appearance, 

 the same as that of variola in the sheep, but the difference in 

 the degree of virulence was most marked, the difference being 

 due to the number of virulent granules in a given quantity of 

 matter. After inoculating a sheep with the virus of ovine 

 smallpox, he remarked : — " At the commencement the irritation 

 is distinctly limited to the skin itself, extension of the morbid 

 process ultimately involving the subcutaneous connective tissue. 

 If one of the variolous vesicles is excised at this initial period, 

 when the skin is only red and slightly swollen, and the traces 

 of the gelatinous substance which is beginning to appear on its 

 under surface be removed, then squeezed into a little water on a 

 glass and a healthy sheep inoculated with the matter, the animal 

 will become affected as readily and effectively as if the matter 

 had been extracted from a perfectly developed pustule." 



However astonishing these experiments may appear to us, we 

 cannot help accepting them, because they do not stand as hav- 

 ing been observed by one only, for they are corroborated by 

 Cohn, who also found, on examination of perfectly fresh 

 smallpox lymph, the presence of bioplasts most carefully pre- 

 served. Karstein, also a CTcrman, corroborates this view, and 

 believes that the bacteria are developed from altered cells, the 

 mode of development of the cells depending upon the chemical 

 nature of the cell-liuid, an<l the matter and force acting from 

 without. The contagium of the virulous agent of Variola Ovina, 

 when once it enters a flock, has no preference for one animal 

 more than another, but towards the close the virus loses its 

 potency and becomes, to a very great extent, weakened by 

 transmission, and some of the tlock offer mild and incomplete 

 symptoms of the disease. 



Symptoms. 



This disease is develo]>ed by various characteristic and distinct 

 stages — incubative, febrile and pa])uhir, vesicular, pustular, and 

 desquamative. During the incui»ative stage, the symptoms, 

 whit'li are of a local and general kind, are obscure, and we are 

 unable to nuike a diagnosis for a time after exposure to the 

 contagion. The period between the imjilantiug of the di.^ease 



