(534) 
fogreata Philorophtr, and fo experienc*d aChyniiftJ induce 
hiai to call them Sufpiciom , yet the grounds he produces feem to 
raife them to the priviledgcs of Jjfertms : And though , as a late 
Obferver on thefe Trafts faies on the fame fubjeft , 'tis only for the 
Sons of Art to make fuch difcovcries, and indeed the difficulty 
appropriates it to them ; yet the meaneft perfon may enjoy the 
bencfitsof fuch performances, as we find in the difco very andufe 
of the (^AgfjetickJSteedle. For, it cannot be imagined , what im- 
mcnfe profit may follow the knowledge of agreement between 
fomeCeleflia! and Terreftrial Bodies ; flrange efFefls will be then 
aseafily produced, as now they are difficult to imagine. And truly 
this never enough celebrated Author, in his late Effay of HiJIcrical 
reUtms , Obfervatiom and Experiments of CeleJIial and jierial 
Magnets^ the growth of Mettals in their Oar expofed , (they fay 
Corn will foincreafe in Mow's by fvveating, and Coals in heaps) 
^tid thefe Experiments ^ feems to have put it out of doubt, that 
there are fome Hidden qualities in the Air : But ftill the queftion 
returns, what they are ; what their peculiar Effefts and Caufes ; 
and I fear, thefe will long continue but Sufpieions. 
Mydefign in this Paper ( becaufethe place of my refidence 
at prefent denies me conveniencies for attemj ting the other kind 
of proof j is, to maiiifeft i that fuch Sufpieions, and their 
grounds, the Experimencs, may be reconciled to fome received 
Theories ; And as it is the bufinefs of the Honourable perfon to 
fhfew, they are highly countenanced by Experiments \ fo it ftall 
be mine, to make it appear, they are cenfiftent with i]^/^i>//&(f/^j, 
and with the Nature of the bodies in which they are prefumed to 
refide. 
Gorrofions of bodies , efpecially with a fenfible motion , by 
emitting effluvia, which may a!fo be fpringy themfelves, if faline, 
may further bend the, fpringy particles of the Air, giving it a 
greater Elatery, On the contrary, other corrofions not fo emit- 
ting , by differ'ent waies may weaken this fpring ; which efFeft, 
though at firft fight it may feem irreconcileable, may be lefs impof- 
fible, if we conceive the particles of the corroding liquor or 
menftruum, of fuch a penetrating and dividing nature , ( the EflTay 
of Effluviums mdimfe^'mg there are fuch, | as by cutting or wear- 
ing of the ramous or ftifF parts of theAerious corpufcles, which 
ilius beingfmallerj lofe their bent, and become better qualified 
