fuch afsviftnefsythat it will be able to carry it to a great 
diftance : And becaufe fuch a Valve fhutting a great hole 
would prove very difficult to be opened, when the pipe A A 
is of a great Bore, the aperture towards D may be left much 
fmaller than the pipe ; the fwiftnefs of the Air being fo great, 
that even tlirough a pretty fmall aperture, it prelTes the 
lead D as freely almoft as if the whole Bore was quite open. 
Having prepared a Barrel carrying a lead of 2 ounces, the 
Experiment was fhewn before the Royd Society , and the 
Efteft was found very confiderable, the force being little lefs 
than that of the Wind-Gun by compreffion ; tlie fame experi- 
ment being afterwards repeated with a longer Barrel, 'twas 
found that the length in this way of fhooting was very little, 
if any advantage. 
fart of a LETTER from Dr. Salomon Reifel, 
Chief Phyftcian to the Duk^ of Wirtemburg, aboia an 
extraordinary TmGtuvcgiz^en to a S tone : Stutgardi^y 
Febr. 120. 16^6. 
' A Urifaber Stutgardianus, qui & gemmis & Metallicis ty- 
Xjl pis nummorum cudcndorum infculpendis artificiofus 
eft, nomine Chrifiofhort^^ MuUery Anno 1685, aurum a^ua re- 
gis fblutum, oleo Tartari prsecipitatum atque edulcoratum^ 
quod aurum fulminans dicunt, dum in fcutella, quam Ma- 
turellam vocant, ex Japidc Chalcedonico coloris unicipellu- 
eidi onychini feu Cornei, vitro pro fufione praeparato rilbro 
mixtum, & aqua fontana imbutum tereret, ad facienda En- 
caufta feu fmaita ; de quibus Anton, Nerim vertentc Andrea 
Frifwy egit lib. 6. Artis Vitraria ; invenit iterato tertium eo- 
dcm labore : quod color pulveris iftius puniccus, qui per 
dies aliquot ficcatus in vafculo manferat, quoufque inter te- 
rendum 
