V01-. XLII.] PHILOSOPHICAL TRANSACTIONS. 6l3 



r shall therefore only add one or two facts I should indeed have mentioned 

 before, when I was speaking of the difficulty of killing some of the tribes of 

 insects and reptiles; which are, that I have myself seen the heart of a viper 

 continue its regular beats more than 6 hours after it had been taken out of the 

 body ; that I have seen that body move and seem alive to all purposes for a great 

 part of the same time, after having lost the heart ; and that I have seen wasps, 

 whose heads had been taken off, creeping in the window the next day ; and 

 butterflies that have lived, and attempted even to fly, several days after under- 

 going the same severe operation. 



Insects seem at first to suffer but little from the loss of their hinder parts, 

 though these contain most of their viscefa; nor does the loss of limbs seem to 

 affijct them in any proportion to the more perfect animals. But even in our 

 own kind, in infancy, before the parts have lost all their softness, much greater 

 wounds may be received without loss of life, than afterwards. If we go yet 

 further back to our embryo state, it is very probable, that yet vastly greater 

 hurts are recoverable; and it is on that principle chiefly, that the best and most 

 likely account has been given by modern writers in anatomy, of some ve y 

 remarkable monsters that have appeared in the world, where even some of 4he 

 most essential parts of two foetuses have been seen wonderfully united in one 

 and the same body. 



y/ Synopsis of the Calculation of the Transit of Mercury over the Disk of the 

 Sun, Oct. 25, J 743. By Mr. John Catlyn. N"* 466 p. 235. 



The equal time of the true cS at Greenwich Oct. 24'* 22^ 15™ 58* 



The equation of natural days add l6 11 



Apparent time of the true ^ Oct. 24 22 32 Q 



At which time the true place of the sun and of Mercury 



seen from the earth n^ 12° 36' 44" 



The geocentric latitude of Mercury south 9 37 



Elongation in 5 hours, i. e. the 2^ immediately preceding 



and following the (5 2Q 1 6 



Difference of latitude in the same time 4 24 



Therefore the angle of the apparent way of 5 with the ecliptic 8 33 O 

 And the distance of their centres at the time of their nearest 



approach g 31 



And the motion of interval between that and the (5 1 26 



And the hourly motion of Mercury in his path over the sun's disk 5 55-^ 

 And the motion of the 4 duration from the first to the last 



exterior contacts of the limbs 13 15 



