FAMILIAR 



LETTERS ON CHEMISTRY; 



LETTER I. 



MY DEAR SIR: 



The influence which the science of chemistry exercises upon human industry, 

 agriculture, and commerce ; upon physiology, medicine, and other sciences, is now 

 so interesting a topic of conversation every where, that it may be no unacceptable 

 present to you, if I trace in a few familiar letters, some of the relations it bears to 

 these various sciences, and exhibit for you its actual effects upon the present social 

 condition of mankind. 



In speaking of the present state of chemistry, its rise and progress ; I shall need 

 no apology, if, as a preliminary step, I call your attention to the implements which 

 the chemist employs the means which are indispensable to his labors and to his 

 success. 



These consist, generally, of materials furnished to us by nature, endowed with 

 many most remarkable properties fitting them for our purposes. If one of them ia 

 a production of art, yet its adaptation to the use of mankind the qualities which 

 render it available to us must be referred to the same source as those derived 

 immediately from nature. 



Cork, platinum, glass, and caoutchouc, are the substances to which I allude, 

 and which minister so essentially to modern chemical investigations. Without 

 them, indeed,we might have made some progress, but it would have been slow ; 

 we might have accomplished much, but it would have been far less than has been 

 done with their aid. Some persons, by the employment of expensive substitutes, 

 might have successfully pursued the science ; but incalculably fewer minds would 

 have been engaged in its advancement. These materials have only been duly 

 appreciated and fully adopted within a very recent period. In the time of Lavoisier, 

 the rich alone could make chemical researches ; the necessary apparatus could only 

 be procured at a very great expense. 



And first, of glass. Every one is familiar with most of the properties of this 

 curious substance its transparency, hardness, destitution of color, and stability 

 under ordinary circumstances. To these obvious qualities we may add those 

 which especially adapt it to the use of the chemist, namely, that it is unaffected 

 by most acids or other fluids contained within it. At certain temperatures it 

 becomes more ductile and plastic than wax, and may be made to assume in our 

 hands, before the flame of a common lamp, the form of every vessel we need 

 to contain our materials, and of every apparatus required to pursue our ex- 

 periments. 



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