151. Connecticut Agricultural Experiment Station, Annual Report, 1887, pp. 145, et seq.

152. Division of Chemistry, Bulletin No. 38, pp. 60, et seq. The figures are from original drawings under the direction of Prof. Hilgard.

153. Op. cit. supra, pp. 65–69.

154. Op. cit. 13, p. 150.

155. Op. cit. 31, p. 152.

156. Op. cit. 31, p. 157.

157. Op. cit. 31, p. 159.

158. Connecticut Agricultural Experiment Station, Annual Report, 1888, p. 154.

159. Loughridge, Proceedings American Association for the Advancement of Science, Vol. 22, p. 81.

160. Whitney, United States Weather Bureau, Bulletin No. 4.

161. Whitney, op. cit. 40.

162. Vid. 40.

163. Vid. 40.

164. Vid. Anleitung zur Mineralogischen Bodenanalyse von Franz Steinreide; and Mikroskopische Physiographie von H. Rosenbusch.

165. Elemente einer neuen Chemisch-Mikroskopischen Mineral und Gesteinsanalyse, 1877.

166. Rosenbusch, Mikroskopische Physiographie, Plate 11, Fig. 3. The figures of crystals of potassium, sodium, calcium, magnesium, etc., are taken from the same work, Plates 10, 11, and 12.

167. Williams, American Journal of Science, February 1893, p. 203.

168. Op. cit. 46, S. 231.

169. Op. et., loc. cit. 48.

170. Op. cit. 46, S. 233.

171. Op. cit. 46, S. 235.

172. Op. cit. 46, S. 236.

173. Op. cit. 46, S. 237.

174. Op. cit. 46, S. 232.

175. Manuscript Communication from R. L. Packard.

176. Op. cit. 46, S. 241.

177. Op. cit. 46, S. 242.

178. Op. cit. 46, S. 243.