ACKNOWLEDGMENTS. 
The author would express his thanks to his friend Dr. 
Peter Collier, Professor of Chemistry in the University 
of Vermont, for a large share of the calculations and re- 
ductions required for the Tables pp. 150-6. 
Of the illustrations, fig’s 3, 4, 5, 7, 47, 63, and 64, were 
drawn by Mr. Lockwood Sanford, the engraver. For oth- 
ers, acknowledgments are due to the following authors, 
from whose works they have been borrowed, viz. : 
ScHLEIDEN.—Fig’s 10, 13, 17, 19, 30, 48, 49, and 50, 
Physiologie der Pflanzen und Thiere. 
Sacus.—Fig’s 56 and 65, Sitzungsberichte der Wiener 
Akademie, XX XVII, 1859, and fig’s 22, 38, 40, 41, 42, 
43, 59, 66, 69, 70, and 71, Haperimental-Physiologie der 
Pflanzen. 
Payen.—Fig’s 11, 12, and 23, Precis de Chimie Indus. 
trielle. 
Ducuartre.—Fig’s 60 and 61, Eléments de Botanique. 
Ktun. — Fig’s 18, 21a, 29, and 34, Hrndhrung des 
Rindwiehes. 
Hartie.—Fig’s 20, 21b, 32, Hntwickelungsgeschichte 
des Pflanzenkeims. 
Unerr.—Fig. 26, Sitzungsberichte der Wiener Akade- 
mie XLIII, and fig. 55, Anat. u. Phys. der Pflanzen. 
Scuacut.—Fio’s 33, 37, 44, Anatomie der Gewachse, 
fio’s 51, 53, 54, and 62, Der Bawm, and fig’s 52, 57, ana 
58, Die Kartoffel und thre Krankheiten. 
Henrrey.—Fig’s 36 and 39, Jour. Roy. Ag. Soc. of 
England, Vol. XTX, pp. 483 and 484. 
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