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erted ;* and as fevers, or even actual combustion^, have arisen with us from a cer¬ 
tain peculiar state, or combination of the elements, which in moderation, create 
is obvious how difficult it must be to acquire this extensive knowledge of nature; more especially since 
modern discoveries have exhibited to us an infinity of modifications in our processes, and have shewn 
that results may vary with such facility, that even the absence or presence of light will render them 
very different. 
As long as chemistry was confined to the knowledge of a few substances, and was busied only in 
attending to a certain number of facts, it was possible to draw up tables of affinity, and to exhibit the 
result of our knowledge in one and the same table. But all the principles upon which these tables 
have been constructed, have received modifications; the number of principles has increased; and we 
find ourselves under the necessity of labouring upon new ground. A sketch of this great work may be 
seen in the Essay on Affinities of the celebrated Bergman, and in the article Affinity in the Encyclopede 
Methodique. 
Law V. When two or more bodies unite by the affinity of composition , their temperature 
changes. 
This phenomenon cannot be explained but by considering the fluid of heat as a constituent principle 
of bodies, unequally distributed among them; so that, when any change is produced in bodies, this 
fluid is displaced in its turn, which necessarily produces a change of temperature. 
* God governs by second causes, says the great Newton, and it certainly argues in that being 
most power to endow matter with such properties as may serve the intentions of the Creator, without 
his being obliged every moment to be adjusting its component parts, and animating the wheels of that 
stupendous machine. Equally is Nature dependant upon his will:—for if he ceased his energy, matter 
would instantly lose its power. A child keeps on beating his top, and it spins round. God but wills, 
and the great globe moves round its own axis, and describes its appointed circuit, until matter loses the 
power delegated to it by the same will, which first implanted it. 
f At first, the food taken into the stomach retaining its peculiar qualities, irritates the inner coat 
of that organ, and occasions a contraction of its two orifices. The food, thus confined, then under¬ 
goes a constant agitation by means of the abdominal muscles, and of the diaphragm, and by the motion 
of the fibres of the stomach itself. By these movements every part of the food is exposed to the 
action of a fluid secreted in the stomach, called the gastric juice, which (as water dissolves sugar) gra- 
- dually dissolves and attenuates the food (as presently will be proved), and prepares it for its passage 
into, and farther change in, the intestines. 
Our aliment is therefore broken down in the stomach into its constituent principles, and these com¬ 
minuted parts then enter and pass along the capillaries of the intestines, which are incapable of admit¬ 
ting any substance, unless in an highly attenuated or aerial form. 
The anatomical lecturer at Pisa, in the year 1597, happening to hold a lighted candle near the sub¬ 
ject he was dissecting, on a sudden the vapours that issued from the stomach and intestines were set 
on fire. In the same year Dr. Ruisch was dissecting a woman, and had no sooner opened the stomach, 
than there issued out a yellow greenish flame, supposed to have arisen from the vapours, which were 
kindled by a student’s holding a lighted candle near him. 
Dr. Vulpare, the anatomical professor at Bologna, affirms that any one may see, issuing from the 
stomach of an animal, a vapour that burns like spirits of wine, if the upper and lower orifices are 
bound fast with a tight thread. The stomach thus tied up, must be cut immediately under the upper 
ligature, the contents of the stomach being first pressed with both hands, so as to pass to one side. A 
candle being held about half an inch from the aperture, a flame will be observed immediately to issue 
from the stomach. 
Bartholine relates the case of a person, who having drank much brandy for a wager, died, after an 
eruption of a flame of fire had issued from his mouth. The inflammable woman of Coventry, as 
described by Mr. Wilmer, appears also to have reduced herself by dram-drinking to such a state as to 
be capable of being set on fire, and burn like any very combustible matter; so eager, says the learned 
Dr. Beddoes, were the principles of which she was composed to combine with oxygen. 
2 P 
