( % ) 
Sugar diffolved like Salt kills them alfo, if ufed in the 
fime manner, and with that feme dye flat, and fome 
dye round. 
Sack will kill them, but not Co fpeedily as the other 
Liquors. If I had had time, I might have fet down 
many more Obfervations of this kind, to ihew the Sen- 
Ability of theft, and £uch like Animalcula. 
IV. The manner of making Steel, and its Tem- 
per ; with a Guefi at the way the Ancients 
ufed to Steel their Picks*) for the cutting or hew- 
ing of Porphyry. Communicated by Martin 
Lifter, M.D. and S. R. $. 
IN the Philofbphical Tranfa£tions,Numb. 93. p. 601 5% 
amongft other Defiderata's and Queries, are thefe ; 
To endeavour to retrieve the Art of Hardning and Tern* 
pering of Steely for cutting of Porphyry, &c. We 
know not which way to rough-hew Stones of that un- 
traceable hardnels. 
Thofe famous and ftupendious Monuments of Antique 
ty, the ^Egyptian Obelisks are of Porphyry, and moft of 
them curiouily Carved with a vaft number of Figures,one 
way of Writing of the Ancient ^Egyptians: Thefe Wit- 
nefs the Facility that Nation had of graying in Porphyry ; 
a Stone which no Tool will now touch, nor nothing lefs 
affect, than Emery or Diamant Powder. 
Mr.B.ay afluresus, That all the Obelisks of Rom that 
are. Graven with Hieroglyphicks, are of one two. trip " 
kind of Stone, viz. a Marble of a n 
and White, very hard, and hath not in lb ma 
fufiered the lead by the. Weather. 
