rial and Engineering Chemistry_, September, 1916.

Kekule tells how he discovered the constitution of benzene in the
_Berichte der Deutschen chemischen Gesellschaft_, V. XXIII, I, p. 1306.
I have quoted it with some other instances of dream discoveries in _The
Independent_ of Jan. 26, 1918. Even this innocent scientific vision has
not escaped the foul touch of the Freudians. Dr. Alfred Robitsek in
"Symbolisches Denken in der chemischen Forschung," _Imago_, V. I, p. 83,
has deduced from it that Kekule was morally guilty of the crime of
OEdipus as well as minor misdemeanors.

CHAPTER V

Read up on the methods of extracting perfumes from flowers in any
encyclopedia or in Duncan's "Chemistry of Commerce" or Tilden's
"Chemical Discovery in the Twentieth Century" or Rogers' "Industrial
Chemistry."

The pamphlet containing a synopsis of the lectures by the late Alois von
Isakovics on "Synthetic Perfumes and Flavors," published by the Synfleur
Scientific Laboratories, Monticello, New York, is immensely interesting.
Van Dyk & Co., New York, issue a pamphlet on the composition of oil of
rose. Gildemeister's "The Volatile Oils" is excellent on the history of
the subject. Walter's "Manual for the Essence Industry" (Wiley) gives
methods and recipes. Parry's "Chemistry of Essential Oils and Artificial
Perfumes," 1918 edition. "Chemistry and Odoriferous Bodies Since 1914"
by G. Satie in _Chemie et Industrie_, vol. II, p. 271, 393. "Odor and
Chemical Constitution," _Chemical Abstracts_, 1917, p. 3171 and _Journal
of Society for Chemical Industry_, v. 36, p. 942.

CHAPTER VI

The bulletin on "By-Products of the Lumber Industry" by H.K. Benson
(published by Department of Commerce, Washington, 10 cents) contains a
description of paper-making and wood distillation. There is a good
article on cellulose products by H.S. Mork in _Journal of the Franklin
Institute_, September, 1917, and in _Paper_, September 26, 1917. The
Government Forest Products Laboratory at Madison, Wisconsin, publishes
technical papers on distillation of wood, etc. The Forest Service of the
U.S. Department of Agriculture is the chief source of information on
forestry. The standard authority is Cross and Bevans' "Cellulose." For
the acetates see the eighth volume of Worden's "Technology of the
Cellulose Esters."

CHAPTER VII

The speeches made when Hyatt was awarded the Perkin medal by the
American Chemical Society for the discovery of celluloid may be fou