First principles of chemistry for the use of colleges and schools / by Benjamin Silliman.

  • Silliman, Benjamin, 1816-1885.
Date:
1861
Catalogue details

Licence: Public Domain Mark

Credit: First principles of chemistry for the use of colleges and schools / by Benjamin Silliman. Source: Wellcome Collection.

Provider: This material has been provided by the National Library of Medicine (U.S.), through the Medical Heritage Library. The original may be consulted at the National Library of Medicine (U.S.)

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    _/; , | t | 1 P _j /■; | /I y—fc- Fig. 35. Fig. 36. Fig. :;7. Fijr. 39. the lour lateral. The two basal faces are squares, the four lateral are parallelograms. The axes con- nect the centres of opposite faces, and intersect at riglit angles. Square prisms vary in the length of the vertical axis, (a, a,) which is hence called the varying axis; the lateral axes (bb, ce) are equal This class is also called the dime'tric, (dis, twofold, and metron, measure.) 46. The third class contains the rhombic prism, (fig. 37,) the rectangular prism, (fig. 38,) and the rhombic octahedron, (fig. 39.) The rhom- bic prism (fig. 37) has two sorts of edges, two acute and two obtuse. The solid angles are, therefore,of two kinds, four obtuse and four acute. The axes are unequal and cross at right angles. The lateral connect the centres of opposite edges, bb, a: The basal faces are rhom- bic. The rectamjidar prism (fig. 38) has all its solid angles similar. There are three kinds or sets of edges, four lateral, four longer basal, and four shorter basal. The axes connect the centres of opposite faces, and intersect at right angles. The three are unequal. The rhombic octahedron (fig. 39) has three unequal axes, connecting opposite solid angles. All the sections in this solid are rhombic. This class is also called the trimetric, from tris, threefold, and metron, measure. 47. The fourth class contains the oblique rhombic prism, (fig. 40,) and the right rhomboidal prism, (fig. 41.) The oblique rhombic prism is represented in the figure as inclining away from the observer, the prism being in posi- tion when standing on its rhombic base. The upper and lower solid angles in front are dissimilar, one obtuse and the other acute. The four /■ i.-, e-' _-l. __!, Fig. 40. Fig. 41. 45 What are the forms of the second class? Describe them. 46. What form's make up the third class? Describe them. 47. What forms doea the fourth class contain ? How do they differ ?