AMERICAN INSTITUTE. 477 



once a vast cauldron of burning meltetl lava, now crystalized in the form of 

 Basaltic green stone slate. This stone is diificult to work, no doubt of 

 that, but a monument made of it will stand the very longest. Brooklyn 

 Heights have this rock. Enormous boulders of it are found there imbed- 

 ded in earth. I observed one where a cellar was dug for a house ; it 

 weighed two hundred tons. Portions of this rock are ferruginous, porous, 

 and will decay ; so does some of our granite ; that of the monument on 

 Bunker's Hill shows it already ! It has metallics in it with the feldspar 

 and mica and silex ; it is partially itself an oxide ; any granite thus formed 

 is not durable. Marble, also, has its difficulties, its base, calcium ; is 

 acted on by sulphuric acid ; it is a carbonate of lime ; it is not a good ma- 

 terial for costly edifices in cities, whose eternal fires diffuse in the air per- 

 petual supplies of acid which gradually attacks the marble nitric, muriatic 

 and carbonic acids ; all take a share in the mischief, which slowly sloughs 

 off the exposed surfaces. These acids are plenty ; we drink some at Sara- 

 toga ; we find like waters in Texas, in the Bocky Mountains, and as well 

 as springs of Soda, injurious, without the muriatic, to men and animals ; 

 bad for us, as salseratus of our bread is condemned by our Dentists, as 

 hurtful to our teeth. I do not profess to be deep in chemical science, I have 

 said what I know and believe to be useful for us to know. 



Electrotyping, the subject of the meeting, was called up. 



But before that, by request of members, Mr. Breisach read his paper on 

 Ehrenberg, viz : 



The great German Naturalist, Christian Godfrerd Ehrenberg, 



the Creator of a new Science. 



THE MICROSCOPICAL WORLD. 



■_ The researches in one of this most difficult branches of science, commenced 



already 150 years ago, and were continued on larger scale on the beginning 



of this century, but the whole that has been performed, is overshadowed 



by the extraordinary labors, the unperishable zeal, and untiring activity of 



the Naturalish, Ehrenbert. 



Born in April, 1795, in the little town Dchbisch, in Saxonia, he re- 

 ceived his preparatory education at Pforta, and entered the University of 

 Leipzig, in the year 1815. At an early age, he manifested a strong bias 

 for the study of natural sciences — he thus became a student of medicine, 

 and received his Diploma as Physician, in the year 1819. His thesis was 

 '' A New System of Moulds," which on publication, created a sensation in 

 the scientific world. He described in this pamphlet 240 difi"erent forms of 

 microscopical plants, which, before his researches became public, were 

 taken as Infusoria. It attracted the attention of the Prussian Academy of 

 Science, and in consequence, he was recommended for similar investiga- 

 tions, which were intended to be made in Egypt. The Prussian Govern- 

 ment sent him, at its expense, to that country and extended its period 

 after two years of his stay there — to six years. The result of his labors 

 were published on his return, in his " Symbolae Physica," " On the Corals 

 of the Red Sea," and its Akoliphia. 



