226 THE INTELLECTUAL RISE IN ELECTRICITY. 



raphy, written by Griselini, and published about 1760. It 

 appears to have contained, first, a mass of scattered data 

 (probably lecture notes), followed by 140 propositions, 

 based on magnetic phenomena. They relate to the dis- 

 covery of the two points or poles of greatest attraction on 

 the magnet by means of the inclined magnetized needle 

 and to the u new generation of the same;" to magnetic 

 attraction and repulsion, and the communication of mag- 

 netism, both from the lodestone and from magnetized 

 iron ; to the increase of magnetism in magnetic bodies ; to 

 the action of one magnet upon another ; to the various 

 effects produced "in the sphere of the horologe through 

 different positions of magnetized bodies with respect to 

 it;" 1 to the irreparable loss of magnetism which happens 

 in the lodestone and in magnetized bodies when submitted 

 to fire ; and, finally, to the magnetization of iron, by 

 means other than by rubbing it with a lodestone. 



Another volume of Sarpi's writings, the original of 

 which was also destroyed in the same fire, contained 674 

 propositions or "Pensieri" on all kinds of subjects, per- 

 taining to every branch of natural science. Fortunately, a 

 copy 2 was made of this before its destruction, which is now 

 in the Library of St. Mark in Venice. Accompanying the 

 manuscript are notes, made during the last century, in 

 which Sarpi's discoveries are compared with those then 

 claimed by Peter Van Musschenbroeck of Leyden. This 

 gives a little clearer idea of Sarpi's investigations, in that 

 it states that he determined the reciprocal relation of one 

 magnet upon another, but did not measure or determine 

 the magnetic force: also the action of the magnet on iron: 

 also the manifestation of magnetic activity around the 

 poles as an atmosphere or in other words the field of 

 force: also the maximum and minimum of attractive force 

 of the magnet on the iron according to the magnitude of 



1 This may possibly relate to the supposed rotary sphere of Peregrinus. 



2 Class II., No. cxxix., cited by Bertelli, Mem. Sopra Peregrinus, p. 88. 



