ii. SEMINAL VERMICULI. 43 
nore affected by the fenfible influence of this 
element, and fooner yielded under it than thofe 
within the apartment, where the air was lefs agi« 
tated. My fuppofition was erroneous ; for, put- 
ting out two glafles with the fame femen, 
equally expofed to the air, and only with 
the difference, that one was in the funfhine 
and the other in the fhade, thofe in the fun al- 
ways died fooner than thofe m the fhade. Fur- 
ther: a divifion was put in the feminal fluid of 
the fame glafs, feparating it into two parts, fo 
that one was expofed to the funfhine and the 
other was not ; it uniformly happened, that the 
vermiculi of this latter portion iong furvived thofe 
ef the other. 
Attentively contemplating that in the folar rays 
with the naked eye, I fufpected another. caufe, 
The femen both greatly diminifhed, and became 
denfer ; likewile, the colour changed. This in- 
creafed denfity might be prejudicial. An eafy 
method was employed to afcertain the fact, which 
was to prevent the evaporation of the femen in 
the fun, becaufe the denfity might be occafioned 
by evaporation of the more volatile parts; and 
my purpofe was attained by hermetically iealing 
feveral capillary tubes full of femen, and then ex- 
pofing them to the fun, along with another por- 
tion of femen in a watch-glafs. The thermome- 
ter ftood at 73° in the fun. Thofe in the watch- 
| glafg 
