CHYMISTRY. 



108 



sway overall the arts which minister to the com 

 fort and improvement of social life, and over 

 every species of animate and inanimate matter, 

 within the range of human investigation. &quot; The 

 forms and appearances,&quot; (says Sir Humphrey 

 Davy,) &quot; of the beings aud substances of the 

 external world, are almost infinitely various, and 

 they are in a state of continued alteration. Even 

 the earth itself, throughout its whole surface, 

 undergoes modifications. Acted on by moisture 

 and air, it affords the food of plants ; an immense 

 number of vegetable productions arise from ap 

 parently the same materials ; these become the 

 substance of animals; one species of animal 

 matter is converted into another ; the most perfect 

 and beautiful of the forms of organized life ulti 

 mately decay, and are resolved into inorganic 

 aggregrates; and the same elementary sub 

 stances, differently arranged, are contained in 

 the inert soil, or bloom and emit fragrance in 

 the flower, or become in animals the active 

 organs of mind and intelligence. In artificial 

 operations, changes of the same order occur; 

 substances having the characters of earth, are 

 converted into metals ; clays and sands are united, 

 so as to become porcelain ; earths and alkalies 

 are combined into glass ; acrid and corrosive 

 matters are firmed from tasteless substances ; 

 colours are fixed upon stuffs, or changed, or made 

 to disappear; and the productions of the vegeta 

 ble, mineral, and animal kingdoms are convert 

 ed into new forms, and made subservient to the 

 purposes of civilized life. To trace, in detail, 

 these diversified and complicated phenomena; 

 to arrange them, and deduce general laws from 

 their analogies, is the business of chymistry.&quot; 

 Elements of Chymical Philosophy. 



Cliymists have arranged the general forms of 

 matter into the four following classes. Theirs? 

 class consists of Solids, which form the principal 

 parts of the globe, and which differ from each other 

 in hardness, colour, opacity, transparency, densi 

 ty, and other properties. The second class consists 

 of Fluids, such as water, oils, spirits, &c., whose 

 parts possess freedom of motion, and require 

 great mechanical force to make them occupy a 

 smaller space. The third class comprehends 

 Elastic Fluids, or Gases, which exist freely in 

 the atmosphere; but may be confined by solids 

 and fluids, and their properties examined. Their 

 parts are highly moveable, compressible, and 

 expansive ; they are all transparent ; they pre 

 sent two or three varieties of colour ; and they 

 differ greatly in density. The fourth class 

 comprehends Ethereal Substances, which are 

 known to us only in their states of motion, when 

 acting upon our organs of sense, and which are 

 not susceptible of being confined. Such are the 

 rays qf tight, and radiant heat, which are inces 

 santly in motion, throughout the spaces that in 

 tervene between our &quot;lobe and the sun and the 

 tars. Chymists divide the substances in nature 



also into simple and compound. Simple Sub 

 stances are those which have never yet oeen do- 

 composed, nor formed by art. Compound Sub 

 stances are those which are formed by the union 

 of two or more simple substances. The follow 

 ing are all the simple substances, with which we 

 are at present acquainted: Caloric, Light, Oxy 

 gen, Nitrogen, Carbon, Hydrogen, Sulphur, 

 Phosphorus, the Metals, and some of the Earths. 

 AH that I propose, under this article, is, simply 

 to state some of the properties of two or three of 

 these simple substances. 



Caloric, or elementary fire, is the name now 

 given by chy mists to that element or property 

 which, combined with various bodies, produces 

 the sensation of heat, while it is passing from one 

 body to another. This substance appears to 

 pervade the whole system of nature. There are 

 six different sources, from whence caloric may 

 be procured. It may be produced by combus 

 tion, in which process the oxygen gas of the 

 atmosphere is decomposed, and caloric, one of 

 its component parts, set at liberty by friction, 

 or the rubbing of two substances against each 

 other by percussion, as the striking of steel 

 against a piece of flint by the mixture of two 

 or more substances ; as when sulphuric acid is 

 poured upon water or magnesia by electricity 

 and galvanism. The discharge of an electric 

 or galvanic battery will produce a more intense 

 degree of heat than any other means whatever. 

 But the principal, and probably the original 

 source of caloric, is the Sun, which furnishes 

 the earth with a regular supply for the support 

 and nourishment rf the animal and vegetable 

 tribes. From this source it moves at the rate of 

 195,000 miles in a second of time ; for it has 

 been already stated, that the sun sends forth rays 

 of heat, which are distinct from those which pro 

 duce illumination, and which accompany them 

 in their course through the ethereal regions. 



Caloric is the cause of fluidity, in all sub 

 stances which are capable of becoming fluid. A 

 certain portion, or dose of it, reduces a solid body 

 to the state of an incompressible fluid ; a larger 

 portion brings it to the state of an aeriform or 

 gaseous fluid. Thus, a certain portion of caloric 

 reduces ice to a state of water ; a larger portion 

 converts it into steam or vapour. There is 

 reason to believe that the hardest rocks, the 

 densest metals, and every solid substance on 

 the face of the earth, might be converted into 

 a fluid, and even into a gas, were they submit 

 ted to the action of a very high temperature. 

 This substance is called sensible caloric, when 

 it produces the sensation of heat ; and latent 

 caloric, when it forms an insensible part of 

 the substance of bodies. All bodies are. in a 

 greater or less degree, conductors of caloric. 

 Metals and liquids are good conductors of heat, 

 but silk, cotton, wool, wood, &c. are bad conduc 

 tors of it. For example, if we put a short po- 



