( jj? 3 
The lad Propofition fliews how to find the Refra&ion 
of a Ray of&igfil in.it'si pafiage thto’ the Atmofphere, 
upon the Suppofition that Light is a Body, and that the 
Refrta&tdn of it is.caufed By the Attra&ion of the Bodies 
the Rays approach to In this. Propofition there is a re- 
markable inftance of t\ke Ufefulnefs of the Method of 
Increments in finding the Coefficients of a Scries, which 
according to the Valueslof Y certain Symbol, as n, ex- 
press both all the Fluents, and all the Fluxions of a 
certain Quantity. ' ' / f . .'!*tL;od 
II. LuJovici Fei^dinancli Marfilii Dijfertatio de Ge- 
tieratiotie Fdngorum. Vtym: 1 7 1 4, 4to. 
T FIis Author tells us that he gave bis youthful Incli- 
nations to the Study ot tfrd-Mathematicks and 
Obfervations of Nature, under the Tuition of the cele- 
brated Malpighis, and Lelius Trinmfettut Botanick Profefior 
of Bononix : and amongft the various Produ&ionSof Na- 
ture, his chief Delight was in the Contemplation of the 
fudden Growth and various forts of Aftifkrooms which both 
the Earth and Trees brought forth. Of the firft Kind he 
oblerved the greateft Number to arife in Camps, produ- 
ced from the Horfes Dung, and are commonly called 
Fratahtili. . 
In the- Years 1699 and I 7 00 » being then in Croatia 
and Tranfalvania, in the Armies there, he made a large 
Volume of Defigns of Fungi , which he fent to Triuwfetti to 
put in order, who added a great Number to them of fuch 
as he found about Bononia ; yet after all the moll dili- 
gent Search, he could never find them to produce any 
Seed either in their Gills or other Parts. 
The Origin and Generation of Mu[hrooms he fays is not 
eafy to demonftrate, fince both the Ancients and Moderns 
2 dif- 
