On the Construction of Buildings, ete. 215 
A direct determination of the water gave 19'83 peret. These 
analyses give the oxygen ratio 2: 3:2, and the formula 
3(Mg C+H)+Mg H 
which calculated gives faerie 
‘i ie G ir 
44°68 35°86 19:46 
he composition and formula are the same as obtained b 
Kobell and Wachtmeister for hydro-magnesite from Negroponte 
and Hoboken. 
_Ye are not aware that this species has heretofore been observed 
With a crystalline structure. 
10. The supposed Magnesite of Hoboken, shown to be Arragonite. 
In connection with the foregoing investigations, it was thought 
that an examination of some of the anhydrous carbonates of mag- 
pe 
hot unfrequently occurring in delicate needle crystals.) A care- 
W qualitative examination of the needle crystals, showed them 
to be carbonate of lime, with scarcely a trace of magnesia; they 
have the form. of Arragonite. Specimens from Staten-Island 
and the vicinity of Westchester, Pa., were examined, with like 
tesults, The crystals from the serpentine quarry near West- 
chester are frequently transparent and are among the most beau- 
ful specimens of crystallized Arragonite that have been observ: 
in this country. 
Lab. University of Va., Jan. 18th, 1853. 
Arr, XXV.-_A4 Consideration of some of the Phenomena and 
~ Laws of Sound, and their application in the Construction of 
Buildings designed. especially for Musical Effect ;* by J. B. 
Urnam, M.D., Boston. 
* Axcurrecture,” says Thomas Hope in his well known His- 
torical Essay, “is pease dee an art of direct utility.” 
It more than all others adapts itself to the tastes and habits and 
cupations of the people. Everywhere this fitness for a definite 
Object, and adaptation of means to the end is apparent. It is an 
de too, that keeps pace with the progress of the world, and 
fore accept whatever aids Science and Philosophy may offer 
Ms improvement. 
Ps The toni * & r " i ~ 
es discussed in thi formed the subject of a series of articles re- 
Pred publ in Dwicht’s Deal of Music,” under the title of “ Acoustic 
thoughts . They are here given somewhat more at length, with such additional 
48 a further investigation of the matter has furnished. 
