History of Animal Plagues . 313 



' The space of time, likewise, betwixt the beasts receiving the in- 

 fection and the perceptible effects of it, is not yet precisely settled by 

 accurate observations. But there are vi'ell-known facts that give us 

 a considerable degree of information with regard to it. In general, 

 appearances will be found in three or four days ; in some few instances 

 they may not come on till six or seven. We may state the latter time 

 as the utmost period, unless when the beasts are very slightly affected 

 with the disease, and then, where the symptoms may not be discernible 

 till it be in its most powerful state, ten days may be allowed. If a 

 beast, therefore, suspected to have received the infection, do not show 

 any signs of it in six or seven days, there will be very little danger of 

 its being seized ; and if none appear in ten, it may be taken for granted 

 that there is no infection in the case. 



' The time for detaining cattle in any place to which they have 

 been removed, after having been exposed to a risk of the infection, in 

 order to prevent their spreading the disease to other parts, may be 

 therefore limited to a fortnight, since there is not the least hazard 

 after such time of their being seized with the disease, in consequence 

 of their having been exposed to the contagion so long before. 



' These are the general facts and observations respecting the murrain 

 which have hitherto presented themselves. It is proper to subjoin that, 

 as before intimated, this disease has various appearances, symptoms, and 

 degrees of mortality, at dilferent times, and in ditferent places ; as the 

 epidemical effects of the seasons, or endemical circumstances of par- 

 ticular countries, have interfered with the natural process of the disease. 

 In the United Provinces a profuse diarrhoea, or looseness, is a very com- 

 mon symptom, and generally carries off the beasts by exhausting their 

 strength ; but, where they do not recover, it seems to be the critical 

 evacuation by which the virus of the disease is discharged. Eruptions 

 more rarely attend the murrain in that country, though they are not 

 always wanting. On the contrary, in Great Britain the looseness seldom 

 happens, and is mostly a mortal symptom, though, in some few cases, a 

 salutary one. Eruptions occur much more frequently, and are generally 

 the critical deposit of the virus when the beasts recover. In Denmark 

 the disease, when it made its furious attack in 1759, '^^^ ^^'^ more violent 

 and mortal than it was ever known in England or Holland, or than it 

 had been when it infested the same places before. The fatal crisis 

 was then very rapid, the beasts dying in two or three days, and some 

 sooner, after they first appeared to be affected. At some periods, re- 

 markable bhstcrs on the tongue are related to have been an early and 

 general symptom of this disease ; ' they are not near so frequent now, 



' There is, as was above observed, another contagious disease of the cattle, of 



