382 ^ Treat ise on 
where they not only preferve the fermentative Mo- 
tion received in the Stomach, but are alfo thrown 
into a greater Motion by the fpirituous Parts of the 
Blood : They are then mingled with the fulphure- 
ous Parts of the Blood, which they draw into Fer- 
mentation with themfelves, and divide and attenu- 
ate *, and thus diffolve and rarefy the whole Mafs : 
Whence Drowfinefs and Sleep. Nor does Opium 
operate before its divided Sulphur arrives at the 
Blood. It is true, that a certain grateful Senfation 
of Warmth is perceived in the Stomach in a fhort 
Time after taking Opium, from the gentle Titil- 
lation of its faline-oily Parts which are let at Liber- 
ty by the gaftrick Juice *, but Sleep does not come 
on till Half an Hour, or an Hour after ; which 
is the Time required for the Conveyance of the 
fulphureous Particles of the Opium to the Mafs of 
Blood. 
If it happen that the Particles of Opium are re* 
tained too long in the Stomach, or taken in too 
great a Quantity ; then, from the over-ftrong Titil- 
lation and Irritation of the nervous Fibres of the 
Stomach proceeds a Naufea, Hickup, or Vomit- 
ing. 
From thefe Things duly confidered, the Ratio- 
nale of the other Effe&s of Opium will be fuffi- 
ciently clear. I fhall therefore no longer dwell up- 
on their Explanation. 
When Opium hath been taken in too large a 
Dofe, and the grievous Symptoms occafioned there- 
by threaten Death, the Cure ought to be attempt- 
ed, firft by Blood-letting, and in the next Place by 
an Emetick. By this not only the Remains of the 
Opium in the Stomach are thrown up, but alfo by 
the Efforts of Vomiting the nervous Membranes 
are Ihook, and by thofe Succuffions the intercept- 
ed Afflux of the Spirits to the Parts is reftored. 
