ADDITION, BY THE TRANSLATOR. 



IT is proper to inform the Reader, that the preceding EHay has 

 not Mr. Leeuwenhoek for its author, but is taken from a letter writ- 

 ten to liim on th,e lubjedl by G. Bidloo, a profedional gentleman at 

 Leyden, under date of the 21ft March 1698, and publilhed in the 

 Dutch Edition of Mr. Leeuwenhoek's Works, tliough it does not 

 appear in the Latin Verfion ; but, as the fubje61: is interefting, and 

 probably tliis Eday has not before appeared in any other than the 

 Dutch language, the Tranflator thouglit that it might be acceptable 

 to tlie Englifli Reader. 



Since the perufal of this Eflay, the Tranflator lias had opportuni- 

 ties of converfing with feveral judicious Gentlemen, who are conver- 

 fant in the grazing of Sheep, from whom he has collected the follov/- 

 ing particulars : 



That in vei'y wet feafons, particularly towards the latter end of 

 the year, a fpecies of grafs fprings up in the low and wet lands, by 

 feeding on which, the Sheep are fuppofed to contraft the diftemper 

 called the Rot. That, if the rains do not abound, until after the win- 

 ter froft has been experienced, the Sheep are not then obnoxious to 

 this difeafe, but othervvife, if a wet feafon precedes the froft ; and 

 laftly, that Sheep infedfed with this difeafe, do, for a time, appear fat 

 and healthy, but, when tlie diibrder gets to a height, they fall away 

 rapidly. 



Thefe particulars feem to prove, tliat the difeafe called the Rot 

 in Sheep, docs in fa6l proceed from the animal defcribed in the 

 preceding Efi'ay, whic'n, being bred in the water, and adiiering, with 

 its eggs, to the grafs growing in watery places, is fwallov/ed by the 

 Sheep. And, it is probable that wlien the froft precedes a ^vet fea- 

 fon, tlie animalcules and their eggs are killed by the froft, and con- 

 fequently tlie Sheep efcape : we may alfo conclude, that while this 

 noaous anijnalcule is in an infant ftate in the bowels of the Slieep, 



