PROCEEDINGS OF THE POLYTECHNIC ASSOCIATION. 459 



and immediately oxygen, seeking those substances for wliicli it 

 has most affinity, aluminum, silicon, potassium, sodium, &c., would 

 form the centre of the earth. Only after these affinities have been 

 satisfied, in the igneous epoch, could we have carbonic acid and 

 the productions of the carboniferous period. Again, the water 

 when first formed must have been in the form of vapor, and as it 

 became condensed the lime and similar substances would be dis- 

 solved in it, giving us very little dry land. There was then little 

 oxygen in the atmosphere, and therefore vegetable, rather than 

 animal life, was luxuriant. The atmosphere is not a chemical mix- 

 ture. Its composition is remarkably uniform now; but it has un- 

 doubtedly very much changed in the oclation of its constituents. I 

 have no doubt that it will continue to change so as to be suited for 

 higher organizations. Such considerations illustrate a method 

 of vieAving the subject which seems to me to open a vast field of 

 exploration. 



The Chairman remarked that although the science of chemistry 

 has been improved so much since the time when four elements, 

 fire, water, earth, and air, were all that were recognized, yet it 

 remains pre-eminently the great field of investigation in natural 

 science. What will be the result when it begins to investigate 

 the development of the first forms of crystals and of vitalized 

 matter, no one can foresee. 



EXPLOSIVE PROJECTILES. 



The subject of " Explosive Projectiles " was postponed until 

 the next meeting. Adjourned. 



American Institute, Polytechn 



Decern 



i?ic Association, ) 

 Tiber 12, 1861. I 



Mr. Tillman was called to the chair. 



Mr. Butler exhibited specimens of the Franklinite and wrought 

 iron in layers, and remarked that the layers of Franklinite were 

 not as hard as the Franklinite before put it. It seemed as if the 

 hardness had been in part merged into the wrought iron. 



CAMP pan and baker. 



Mr. C. Bush exhibited this cooking and baking utensil, which 

 is of light weight, convenient, and of compact form. It is con- 

 structed with double sides and bottoms, with non-conducting 



