FAMILIAR LETTERS ON CHEMISTRY. 



Then, how admirable and valuable are the properties of cork ! How little do 

 men reflect upon the inestimable worth of so common a substance! How few 

 rightly esteem the importance of it to the progress of science, and the moral 

 advancement of mankind ! There is no production of nature or art equally adapted 

 to the purposes to which the chemist applies it. Cork consists of a soft, highly 

 elastic substance, as a basis, having diffused throughout a matter with properties 

 resembling wax, tallow, and resin, yet dissimilar to all of these, and termed 

 wberin. This renders it perfectly impermeable to fluids, and, in a great measure, 

 even to gases. It is thus the fittest material we possess for closing our bottles, 

 and retaining their contents. By its means, and with the aid of caoutchouc, we 

 connect our vessels and tubes of glass, and construct the most complicated appa- 

 ratus. We form joints and links of connexion, adapt large apertures to small, and 

 thus dispense altogether with the aid of the brass-founder and the mechanist. Thus 

 the implements of the chemist are cheaply and easily procured, immediately 

 adapted to any purpose, and readily repaired or altered. 



Again ; in investigating the composition of solid bodies of minerals we are 

 under the necessity of bringing them into a liquid state, either by solution or 

 fusion. Now vessels of glass, of porcelain, and of all non-metallic substances, are 

 destroyed by the means we employ for that purpose are acted upon by many 

 acids, by alkalies, and the alkaline carbonates. Crucibles of gold and silver would 

 melt at high temperatures. But we have a combination of all the qualities we can 

 desire, in platinum. This metal was only first adapted to these uses about fifty 

 years since. It is cheaper than gold, harder and more durable than silver, infusible 

 at all temperatures ot our furnaces, and is left intact by acids and alkaline 

 carbonates. Platinum unites all the valuable* properties of gold and of porcelain, 

 resisting the action of heat, and of almost all chemical agents. 



As no mineral analysis could be made perfectly without platinum vessels, had we 

 not possessed this metal, the composition of minerals would have yet remained 

 unknown ; without cork and qaoutchouc we should have required the costly aid of 

 the mechanician at every step. Even without the latter of these adjuncts, our in- 

 struments would have been far more costly and fragile. Possessing all these giftd 

 of nature, we economize incalculably our time to us more precious than money ! 



Such are our instruments. An equal improvement has been accomplished in 

 our laboratory. This is no longer the damp, cold, fire-proof vault of the metallur- 

 gist, nor the manufactory of the druggist, fitted up with stills and retorts. On the 

 contrary, a light, warm, comfortable room, where beautifully constructed lamps 

 supply the place of furnaces, and the pure and odorous flame of gas, or of spirits 

 of wine, supersedes coal and other fuel, and gives us all the fire we need ; where 

 health is not invaded, nor the free exercise of thought impeded; there we pursue 

 our inquiries, and interrogate nature to reveal her secrets. 



To these simple means must be added the balance, and then we possess every 

 thing which is required for the most extensive researches. 



The great distinction between the manner of proceeding in chemistry and natural 

 philosophy, is, that one weighs, the other measures. The natural philosopher 

 has applied his measures to nature for many centuries, but only for fifty years 

 have we attempted to advance our philosophy by weighing. 



For all great discoveries chemists are indebted to the balance that incomparable 

 instrument which gives permanence to every observation, dispels all ambiguity, 

 establishes truth, detects error, and guides us in the true path of inductive science. 



The balance, once adopted as a means of investigating nature, put an end to 

 the school of Aristotle in physics. The explanation of natural phenomena by mere 

 fanciful speculations, gave place to a true natural philosophy. Fire, air, earth, 

 and water, could no longer be regarded as elements. Three of them could hence- 

 forth be considered only as significative of the forms in which all matter exists. 

 Every thing with which we are conversant upon the surface of the earth is solid, 

 liquid, or aeriform ; but the notion of the elementary nature of air, earth, and 

 water, so universally held, was now discovered to belong to the errors of the past. 



Fire was found to be but the visible and perceptible indication of changes 

 proceeding within the so-called elements. 



Lavoisier investigated the composition of the atmosphere and of water, and 

 studied the many wonderful offices performed by an element common to both in the 

 scheme of nature, namely, oxygen : and he discovered many of the properties of 

 this elementary gas. 



After his time, the principal problem of chemical philosophers was to determine 

 the composition of the solid matters composing the earth. To the eighteen metals 

 previously known, were soon added, twenty-four discovered to be constituents of 

 minerals. The great mass of the earth was shown to be composed of metals in 



