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 beengborrowed, viz. : 
ScurumEn:—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 V1, Heperimental-Physiologie der 
Pflanzen. 
Payren.—Fig’s 11, 12, and 23, Precis de Chimie Indus- 
trielle, 
Ducuartre.—Fig’s 60 and 61, Lléments de Botanique. 
Kian. —Fig’s 18,-21a, 29, and 34, Erndhrung des 
Rindviehes. ... 
Harrie.—Fig’s. 20, 21b, 32, Hnitwickelungsgeschichte 
des Pflanzenkeims. 
Uneur.—Fig. 26, Sitzungsberichte der Wiener Akade- 
mie, XLITI, and fig. 55, Anat. u. Phys. der Pflanzen. 
Scuacut.—Fig’s 38, 37, 44, Anatomie der Gewaschse, 
fig’s 51, 53, 54, and 62, Der Baum, and fig’s 52, 57, and. 
58, Die Kartoffel und ihre Krankheiten. 
Huenrrey.—fFig’s 36 and 39, Jour. Roy. Ag. Soc. of 
England, Vol. XTX, pp. 483 and 484, 
v 
