VOt. ITI.] PHILOSOPHICAL TRANSACTIONS. 301 



above 3 years, so that whatsoever noise was made, he gave no sign of hearing 

 it. He walked very little, and was so feeble that being unable to lift up his 

 feet, he could only trail his body forward. After the transfusion practised 

 upon him, he remained for an hour upon the table, where he was yet untied ; 

 but leaping down afterwards, he went to find his masters, who were in other 

 chambers. Two days after he went abroad, and ran up and down the streets 

 with other dogs, without trailing his feet as he did before. His appetite also 

 returned to him, and he began to eat more and more greedily than before. 

 But what is more surprising is, that from that time he gave signs that he began 

 to hear, returning sometimes at the voice of his masters. The 13th of June 

 he was almost quite cured of his deafness, and appeared without comparison 

 more jocund than he was before the operation. At length, the 20th of the 

 same month he had wholly recovered his hearing, yet in such a manner that 

 when called, he turned back as if he that had called him had been very far off, 

 though not always so. 



Description of a New Microscope. By Eustachio Dirim. 



iVMS, p,S42. 



Eustachio Divini has made a microscope of a new invention, wherein instead 

 of an eye-glass convex on both sides, there are two plano-convex glasses, so 

 placed as to touch one another in the middle of their convex surface. This in- 

 strument is peculiar in this, that it shows the objects flat and not crooked, and 

 although it takes in much, yet it magnifies extraordinarily. It is almost i6-l 

 inches high, and adjusted at four different lengths. In the first, which is the 

 least, it shows lines 41 times larger than they appear to the naked eye ; in the 

 second go times; in the third 111 times; and in the fourth 143 times. 

 Whence it may easily be calculated how much it magnifies surfaces and soli- 

 dities. The diameter of the field, or the subtense of the visual angle measured 

 upon the object-plate, in the first length is 8 inches 7 lines; in the second 12 

 inches 4 lines ; in the third 13 inches; and in the fourth a little more than l6 

 inches. 



In viewing with this microscope the small grains of searced sand, they per- 

 ceived an animal with many feet, its back white and scaly, but less than any of 

 those hitherto observed: for although the microscope showed every grain of 

 sand as large as an ordinary nut, yet this animal appeared no larger than one 

 of those grains of sand seen without a microscope. 



