FUEL. 



is totally consumed. But it cannot be 

 made to burn so as to produce a gentle 

 heat. If not in considerable quantity, 

 and violently heated, it is soon extin- 

 guished. 



In using 1 this kind of fuel, it is proper 

 to be on our guard against the dangerous 

 nature of the burnt air which arises from 

 charcoal of all kinds. Charcoal burns 

 without visible smoke. The air arising 

 from it appears to the eye as pure and as 

 clear as common air. Hence it is much 

 used abroad by those who are studious of 

 neatness and cleanliness in their apart- 

 ments. But this very circumstance should 

 make us more watchful against its effects, 

 which may prove dangerous, in the high- 

 est degree, before we are aware of it. 

 The air arising from common crude fuel 

 is no doubt as bad, but the smoke renders 

 it disagreeable before it becomes danger- 

 ous. The first sensation is a slight sense 

 of weakness : the limbs seem to re- 

 quire a little attention, to prevent fall- 

 ing. A slight giddiness, accompanied 

 by a distinct feeling of a flush, or glow in 

 the face and neck. Soon after, the per- 

 son becomes drowsy, would sit down, but 

 commonly falls on the floor, insensible of 

 all about him, and breathes strong, 

 snoring as in an apoplexy. If the person 

 is alarmed in time, and escapes into 

 the open air, he is commonly seized with 

 a violent headach, which gradually 

 abates. 



But when the effect is completed, as 

 above described, death vejy soon ensues, 

 unless relief be obtained. There is 

 usually a foaming at the mouth, a great 

 flush or suffusion over the face and neck, 

 and every indication of an oppression of 

 the brain, by this accumulation of blood. 

 The most successful treatment is, to take 

 off a quantity of blood immediately, and 

 throw cold water on the head repeated- 

 ly. A strong stimulus, such as hartshorn, 

 applied to the soles of the feet, has also a 

 very good effect. 



The fifth and last kind of fuel is wood, 

 or fossil coals, in their crude state, which 

 it is proper to distinguish from the char- 

 coals of the same substances. The dif- 

 ference consists in their giving a copious 

 and bright flume, when plenty of air is 

 admitted to them, in consequence of 

 which they must be considered as fuels 

 very different from charcoal, and adapted 

 to different purposes. See FLAME. 



Flaming fuel cannot be managed like 

 the charcoals. If little air be admitted, 

 it gives no flame, but sooty vapour, and 

 a diminution of heat. And if much air 



be admitted, to make those vapours break 

 out into flame, the heat is too violent. 

 These flaming fuels, however, have their 

 particular uses, for which the others are 

 far less proper. For it is a fact, that 

 flame, when produced in great quantity, 

 and made to burn violently, by mixing it 

 with a proper quantity of fresh air, by 

 driving it on the subject, and throwing it 

 into whirls and eddies, which mix the air 

 with every part of the hot vapour, gives 

 a most intense heat. This proceeds trom 

 the vaporous nature of flame, and the 

 perfect miscibility of it with the air. 



As the immediate contact and action of 

 air is necessary to the burning of every 

 combustible body ; so the air, when pro- 

 perly applied, acts with far greater advan- 

 tage on flame, than on the solid and fixed 

 inflammable bodies : for when air is ap- 

 plied to these last, it can only act on their 

 surface, or the particles of them that are 

 outermost: whereas,flame beinga vapour 

 or elastic fluid, the air, by proper contri- 

 vances, can be intimately mixed with it, 

 and made to act on every part of it, exter- 

 nal and internal, at the same time. This 

 great power of flame, which is the conse- 

 quence of this, does not appear when we 

 try small quantities of it, and allow it t 

 burn quietly, because the air is not inti- 

 mately mixed with it, but acts only on the 

 outside, and the quantity of burning 

 matter in the surface of a small flame is 

 too small to produce much effect. 



But when flame is produced in large 

 quantity, and is properly mixed and agi- 

 tated with air, its power to heat bodies 

 is immensely increased. It is therefore 

 peculiarly proper for heating large quan- 

 tities of matter to a violent degree, espe- 

 cially if the contact of solid fuel with 

 such matter is inconvenient. Flaming 

 fuel is used for this reason in many ope- 

 rations performed on large quantities of 

 metal, or metallic minerals, in the making 

 of glass, and in the baking or burning of 

 all kinds of earthen ware. The potter's 

 kiln is a cylindrical cavity, filled from the 

 bottom to the top with columns of wares, 

 the only interstices are those that are left 

 between the columns; and the flame, 

 when produced in sufficient quantity, 

 proves a torrent of liquid fire, constantly 

 flowing up through the whole of the in- 

 terstices, and heats the whole pile in an 

 equal manner. 



Flaming fuel is also proper in many 

 works or manufactories, in which much 

 fuel is consumed, as in breweries, distil- 

 leries, and the like. In such works, it is 

 evidently worth while to contrive the 



