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Show 256 CASSA VI. . d often . and when the tar and grease combmed ~n ls ble i~ water and soap is added, the compoun IS so u ' the spot is removed. . ted in the dry Limestone or mar~le ~ay ~e hear ile that lime :fire, till it become qmck-h~e ' and ~ h ction of beat is hot in the kiln, it _has ant mcredawsei.thacarbonic acid. . .t d .t parts with wa er an t ln I ; ~n. I d f the kiln, the action of be(;)/ After It IS remove rhom ndinO" atmosphere, till is communicated to t e surrou t~m erature . and that and the lime h~ve t~e t s::O~gh the lime takes if the atmosphere IS mms ~lso some vege·water back again out of that. th~o Jat~opha manihot, table substances (sucf ~~ h the Indians of Central of the tuberous roo~s 0 w 1<?' b d and which in its A me rica make their cassavt .rea.' t heat have both . · · ) may by IDOlS ' raw state IS a pmson. ' ther offensive ingre .. the water and the pmson, or o dients, boiled out of them. CASSAVI (JATROPHA MANIHOT). NO GROW'l'II IN MERE MATTER. 257 If, in these cases, any quality which the substanc'-' had previously shall disappear, we may always conclude that that depends on the combination; but if we find it in any substance that has been separated by the process, it is either an original quality of that substance, or it depends on a combination which has not yet been discovered: but which we may find upon further examination. It is thus probable that there is no permanent quality of any thing material; but that all distinctions which are apparent to our senses are the results of combinations, all of which may be dissolved; and when that takes pla<".-e, the old qualities vanish, and new ones become apparent. We find, too, that there are many states of matter that have the power (as we call it) of extending themselves. Combustion, from a match or spark, soon spreads over a vast quantity of combustibles. Fermentation is produced in brewing and baking, by adding yest to the dough, much in the same manner as a crop is obtained by sowing seeds. Canker, begun at a little hurt, will spread till it destroys a tree ; rot from one place will consume an entire beam of timber; a spot of rust will in time destroy a bar of steel ; and a puncture with the fang of a serpent, or a needle merely stained with the corrupt matter of the dead and dissolving body, will breed corruption in the living one, which no surgery can arrest. But these and all the analogous cases are really destructions, and when the process of destruction is over, the power of destruction. as we call it, is nowhere to be found, and all that we can say of it merely is., that it is a state of matter, and no more a kind of matter, or matter as independent existence at an, ~han light, or heat, or gravitation. 'l'he tendency of those decompositions, so far as they go, is to reduce all matter to one state-to bring it to the dust-to prepare it as materials, just V.Q |
