UTILITY OF CHYMICAL KNOWLEDGE. 



of the eighteenth century, the old tedious process 

 of bleaching continued in practice. But, about 

 that period the introduction of the oxymuriatic 

 acid, combined with alkalis, lime and other in 

 gredients, in bleaching cottons and linens, has 

 given an entirely new turn to every part of the 

 process, so that the process which formerly re 

 quired several months for its completion can 

 now be accomplished in a few days, and with a 

 degree of perfection which could not previously 

 be attained. Even in a few hours, that which 

 formerly required nearly a whole summer, can 

 now be effected, and that, too, merely by the 

 action of an almost invisible fluid. As the 

 whole process of bleaching, as now practised, 

 consists almost entirely of chymical agents and 

 operations, every person employed in this art, 

 ought to possess a certain portion of chymical 

 knowledge, otherwise many of its processes 

 would run the risk of being deranged, and the 

 texture of the materials undergoing the process 

 of being either materially injured or completely 

 destroyed. 



The operation of brewing fermented liquors 

 is likewise a chymical process. The student 

 of chymistry will learn how the barley in the 

 first instance is converted into a saccharine 

 substance by malting ; how the fermentative 

 process converts the saccharine to a spirituous 

 substance, and how the latter, by continuing the 

 process, becomes changed into vinegar. He 

 will also learn the means of promoting and 

 encouraging this process, and how to retard and 

 check it, when it is likely to be carried too far, 

 so as to be sure of uniformly obtaining satisfac 

 tory results. In this and in every other process, 

 it must therefore be of importance to acquire 

 some knowledge of the principles of natural sub 

 stances, and of the nature of those changes 

 which take place in the materials on which we 

 operate. In the manufacture of soap, it is 

 reckoned by those intimately acquainted with the 

 process, that many thousands per annum, now 

 lost to the community, might be saved, were the 

 trade carried on upon scientific principles. 

 When a soap boiler is an accomplished chymist, 

 he knows how to analyze barilla, kelp, potass, 

 and other materials, so as to ascertain the pro 

 portion of alkali in each ; and when these arti 

 cles are at an exorbitant price, he will have 

 recourse to various residuums, which he will 

 decompose by chymical means, and use as sub 

 stitutes. He will know how to oxydize the 

 common oils and oil-dregs, so as to give them 

 consistence, and render them good substitutes 

 fo- tallow and how to apportion his lime so as 

 to make his alkali perfectly caustic, without 

 using an unnecessary quantity of that article. 

 The manufacture of candles might also derive 

 advantage from chymical science. It is found 

 that foreign tallows frequently contain a large 

 portion of acid rendering them inferior to the 



English, which, by chymical means may bo 

 purified at a very small expense, and by the 

 proper application of chymical agents, other 

 brown tallows may be rendered beautifully 

 white, and fit for the best purposes.* 



The tanning of hides is now ascertained to 

 consist in impregnating the animal matter with 

 that peculiar principle taken from the vegetable 

 kingdom, called tan, the effect of which is ex 

 plained entirely on chymical principles. It is 

 now known that many substances besides oak- 

 bark, contains tan, and to chymistry we are 

 indebted for the means of discovering with 

 accuracy the quantity of tan which the several 

 astringent vegetables contain. It is supposed 

 not to be improbable, when the manufacturers 

 shall have paid proper attention to chymical 

 science, that the article in question may be pre 

 pared in chymical laboratories, so as entirely to 

 supersede the use of oak bark, since the princi 

 ple of tanning has already been formed artifi 

 cially by a modern chymist.f It is also well 

 known, that to chymical research, the manufac 

 tures of earthen-ware and porcelain are indebted 

 for the improved state in which they are now 

 found. For, the successful management of all 

 their branches, from the mixture of the materials 

 which form the body of the ware, to the produc 

 tion of those brilliant colours with which such 

 articles are adorned is dependent on the prin 

 ciples of chymical science. The celebrated 

 Wedgewood, to whom this branch of manufac 

 ture is so highly indebted, devoted his whole 

 attention to the improvement of his art by the 

 application of his chymical knowledge, of which 

 few men possessed a larger share ; and he has 

 been heard to declare, &quot; that nearly all the diver 

 sified colours applied to his pottery were pro 

 duced only by the oxides of iron.&quot; 



There are few persons to whom a knowledge 

 of chymistry is of more importance than to the 

 Agriculturist. It will teach him to analyse the 

 soils on the different parts of his farm, and to 

 subject to experiment the peat, the marie, the 

 lime and other manures, in order to ascertain 

 the advantages to be derived from them, and 

 the propriety of applying them in particular in 

 stances. It will teach him when to use lime 

 hot from the kiln, and when slacked, how to 

 promote the putrefactive process in his com 

 posts, and at what period to check it, so as to 

 prevent the fertilizing particles becoming un- 

 prolific and of little value. It will also teach 

 him the difference in the properties of marie, 

 lime, dung, mud, ashes, alkaline salt, soap- 

 waste, sea-water and other manures, and, con 

 sequently, which to prefer in all varieties of 

 soil. It is said that the celebrated Lavoisier 



* For most of the above hints the author Is In 

 debted to Mr. Parkes. 



tSegerin. See Nicolson s Phil. Journal, 4to vol. 

 i. p. 271. 



