Miscellan ics. 173 



They are remarkably gregarious, and cluster together in great 

 numbers on barns where they find the jutting of the eaves to suit 

 their convenience. Under these they build their nests, never enter- 

 ing the barn. 



But the most distinguishing trait in their character consists in the 

 mode and form in which their nests are built. The only material 

 which they use for the exterior part is mud. They begin by plaster- 

 ing on the side of the barn about twelve inches below the projection 

 of the eaves. As they ascend in the work, they enlarge it by a grad- 

 ual and handsome swell so that the form is elliptical, and of such a 

 size that the nest would hold a quart. As they proceed in their 

 work and approach the eaves, they contract their domicil, giving it 

 at the same time such a curve as to leave the entrance through a neck, 

 the end of which is turned downward. The aperture is round, about 

 one inch and half in diameter. Every other part of the nest is 

 closed with a sufficient mud wall and ceiling. They are excellent 

 masons as well as peaceable neighbors among themselves, building 

 their nests so that in many instances they are in contact with each 

 other, and in some, considerably lapped, so, however, as not to ob- 

 struct the free ingress and egress of each proprietor. I, this morn- 

 ing, counted twenty two nests upon the south side of one barn, all 

 fully tenanted, and all within a line of twelve or thirteen feet in length. 

 I understand they build their nests only on the southerly side of barns. 



13. JVew pyroj)horus, by Dr. Hare. — ^When Prussian blue is heated 

 to a red heat for about a minute in a glass tube and then sealed up, 

 it constitutes a pyrophorus. As soon as the tube is fractured, and 

 the mass included thrown out upon a table it takes fire. 



Remark. — We presume of course, that if duly prepared and trans- 

 ferred for keeping, to an air tight bottle, it would become ignited if 

 poured out into the air. — Ed. 



14. Transactions of the Albany Institute. — The number for June 

 1830, contains papers on the following subjects. 



An account of a man who lived on water fifty three days, by Js. 

 M. Naughton. 



Monograph of the Cones of the United States, by Prof. Jacob 

 Green, with a plate. 



Observations on the coal formation of the states of New York and 

 Pennsylvania, by Prof. Eaton. 



