the base as a proton acceptor. The new equation us- ing the oxonium ion would then cause a somewhat en- larged view of neutralization as resulting in the forma- tion of solvent.

H+ + OH- --r Hz0 HaO+ + OH- -+ 2Hz0

These might serve as the main outgrowths of one of the experiments described which show indicator ef- fects and neutralization in media other than water.

(D) Demonstrations on Indicator Reactions and Neu- tralimtion

(1) A one per cent solution of basic fuchsin in (a) water and (b) refined glacial acetic acid is the indi- cator used, respectively, in (a) water and (b) refined acetic acid media. Solid oxalic acid is used as the acid and solid sodium acetate as the base. Incidentally,

TABLE 4

Bar* Fuchrin i n Wakr Some Indirolor i n Acdic Arid Renrlloril Il.rrrlU"1

ReozeI1 '010l ReWrnl color

(o ) oxdie acid in water Purple (o) Oralic acidia neetie Purplc mid

(b) Sodium acetate io Pink (b) Sodivm acetate in Pink water m t ~ c acid

(c) Addition of ucenn d i d NaAe (c) Duplication in water of this to purple solution (a). fmm prmedwe CQYKI the same rc- which the u c u r solid peid is re- sults. moved cause. the purple color Chnoga in both medin seem to to disappear and the pink color indicate neutrlizntion. appears.

the fact that NaAc acts as a base with litmus in water and acts as a base in HAc should prove stimulating to pupil inquiry.

(2) The same experiment will also work with methyl orange indicator in methyl alcohol. One or two drops of this indicator are added to either the water or methyl alcohol medium. The same acid and base may be used.

TABLE 5

Mdhrl Orange in Wolrr So,"# Indicnlor in Mdhyl Alcohol Rcaecnr &suu ~ e o g r n l Resull

(a) Oxalic acid in water Red (a) Oxalie Qdd in methyl Red

(a) sodium acetate in water Yellow

(c) Add excess oxalic acid as in Ex- periment 1 and theyellow dirap- pear. and red resit.. The re- verse procedure does not give as

alcohol lb) Sodium neefate in Yellow

methyl alcohol lc) DnpSc.%te (c)-similar result%.

The reverse in which excur sodivm acetate is added to the acid given orange.

good results near yellow as expected.

(3) If these materials are not available the common indicator, phenolphthalein, will give good results with oxalic acid and solid sodium hydroxide used in water and methyl alcohol solvents.

The experiment with basic fuchsin is probably most legitimate and the last one employing phenolphthalein probably the least legitimate. However, the pupils are already familiar with sodium hydroxide and prob- ably with oxalic acid. Since saturated solutions are being dealt with in aU cases, we do not get as marked effects as might be possible with dilute solutions.

ONE HUNDRED HIGH-SCHOOL CHEMISTRY PROJECTS J. 0. DERRICK

Junior College of Augusta, Augusta, Georgia

E ARLY in my teaching career I realized that in (5) WAILE~, "Fun with quicksilver." Popuhr Sci . Monthly, 134, 200-3 (Apr.,l939).

order to the of my I must (6) HAUT, "Bakelite type plastics-A demonstration,'. J. supplement the text and required laboratory CHEM. EDUC., 15, 43 Uan., 1938). work with materials that appeal to a variety of in- (7) HR1eAR AND HARVEY, "Initiation program," s c i . ~mfit , terests. With that in mind I began making a list of 11, 59&9 Uan. 13, 1938).

references covering that students could do at (8) WAILES, "Crime-detection tests for the amateur chemist." Popular Sci . Monthly, 132, 100-1 (Feb., 1938). home, Or in the laboratory after Over a period (9) COLER, "The home lab as a hobby," J. C ~ E M . E~uc., 15,

of ten years some of these references have been ex- 1434 (Mar., 1938). tremely valuable to me, and I am submitting them (10) GLEESON, "Some simple experiments dealing with rates with the hope that they may be of value to other of solution," ibid., 15, 187-90 (Apr., 1938).

teachers, especially those who have not taught long (11) CROUSE. "Exhibits," Sc i . Leaflet, 11,118&9 (May 5.1938). (12) BENNETT, "A simple experiment in coal tar distillation,''

enouxh to accumulate teaching aids and information 1. CXEM. EDUC.. 15. 51516 (Nav.. 1938). suitable for club programs. (13) S ~ ~ R D , "A chemistry dem&tration,'. (Bromine

recovery apparatus), Sci. Leafit, 10,671 (Jan. 28, 1937). (1) ANDERSON, "A high-school project in chemical research," (14) LINCOLN, "A chemical exhibition features synthetic com-

J. CHEM. Eouc., 16, 16&4 (Apr.. 1939). pounds," ibid., 10, 5 5 2 4 (Jan. 7,1937). (Reprint from (2) JoENSON, "CatalysisA demonstration," ibid.. 16, 238-9 J. CHEM. EDUC.).

(May, 1939). (15) PARKER AND URMSTON, "Molecular weight of carbon di- (3) J o m s o ~ , "Simple apparatus far determination of per- oxide," J. CHEM. EDUC., 14, 87 (Feb., 1937).

centage composition," +bid.. 16, 22930 (May, 1939). (16) BURLEIGH, "Photo printing box." Popular Sci . Monthly, (4) Wrulss, "Home tests with dry ice" (Method for making 130, 98 (Feb., 1937).

liquid ammonia), Popular Sci . Monthly, 134, 208-11 (17) SHAW, "Unique electric-arc torch," ibid., 130, 100 (Mar., (Feb., 1939). 1937).

WEAVER, "A chemistry project" (Model filter bed), Sci. Learn, 10, 955-6 (Mar. 18, 1937).

C O ~ M A N , "Cold light brought into the classraom," J. CHEM. Eouc., 14, 236-7 (May, 1937).

EDITOR, "Chemical matchmakers" (Home experiments show strange behavior of catalysts), Popular Sci. Monthlv. 130. 6- (May. 1937). . ..

BILLING&: "iecture demonstration experiments." J. CHEM. EDUC., 14, 375-7 (Aug., 1937). -

FALL, "April fools' day chem party," Sci. Leafit, 11, 54-6 (Sent 73 lW71 ,- -r - . - -, - - - . , .

WAILES, "Spectacular stunts with flames," Popular Sci. Monthly, 131, 72-3 (Sept.. 1937).

REINSTEIN, "Experiments with yeast." Sci. LeqRet, 11, 146-9 (Oct. 7, 1937).

J o m s o ~ , "Liquefying and solidifying sulfur dioxide," ibid.. 11. 2367 (Oct. 21. 1937).

LoNG, . "T~~ break of life" ( A play), ibid.. 11, 186-99 (Oct. 14, 1937).

BERTOLET AND OSER, "A home-made electric furnace," J. CHEM. EDOC., 14,4924 (Oct., 1937).

EVANS, "A chemi~try club program," Sci. Lcaflet. 11, 30&9 (Nov. 4, 1937).

(29) EVANS. "Experimental soap making," J. G E M . EDUC., 14, 534-6 (Nov., 1937).

(30) WAILES, "Fun with explosive gases,"Popular Sci. Monthly, 131, 82-3 (Nov.. 1937).

(31) BAW, "Inexpensive vacuum pump," ibid., 128, 67 (Jan., 1936).

(32) VAIL, "A grain of sand," "Through the lwking glass," "Waterglass" (Three lectures), Sci. Leaflet. 9, 569-79 (Jan. 16, 1936).

(33) KEARNEY, "Dry cleaning and dyeing," Reader's Digest, 27, 99-101 (Aug.. 1935). (Copied from Family Circk.)

(34) LEVESWNTE, "A plan for the open house in chemistry," J. C ~ M . Enuc., 13, 7 2 3 (Feb., 1936).

(35) WAILES. "Chemistry equipment from odds and ends," Popular Sci. Monthly, 128, 4- (Feb., 1936).

(36) MUELLER, "Constmction of a Nelson cell." Sci. Leaflet, 9, 1MX) (Mar. 26, 1936).

(37) DELANEY, "Science fair" (A list of demonstrations), ibid., 9, 1049-53 (Part one), ibid., 9, 1124-8 (Part two), ibid., 9,1154-6 (Part three), (Apr. 16, 23, 30, 1936).

(38) DOWDEN, "A home-made polariscope." Popular Sci. Monthly. 128, 102 (Apr.. 1936).

(39) BENNETT, ABILA, WHITE, AND MCDONAGH, "Home science section." Sci. Leafit. 10. 67-70 (Scot. 24. 1936). . . .

(40) & EDITOR, "HOW to form a science 'dib," ;bid., 10, 42-9 (Sept. 24, 1936).

(41) GLEIM, "The formation of ammonium chloride growths," ibid., 10, 175 (Oct. 15, 1936).

(42) Given by East High Schaol, Sioux City, Iowa, "An unusual assembly program: Chemistry today and tomorrow," ibid.. 10, 3 U (Nov. 12, 1936).

(43) BALXMAN, "The preparation and properties of an alloy," ibid., 10, 398-9 (Nov. 19, 1936). (From J. Home Ec.)

(44) Bmc-, "A bome-made respiration apparatus," ibid., lo, 434-7 (Dec. 3. 1936).

(45) LYANS, l project^ in a high-school chemistry course." J. CH~M Eouc., 13, 564 (Dec., 1936).

(46) FILLINOER, "Lead trees with roots in the ground," &id., 12, 92 (Feb., 1935).

(47) JAMES, "Lecture demonstration of the law of combining volumes," ibid., 12, 87 (Feb., 1935).

(48) ANON., "A student gives a method of plating with cadmium and zinc," Sci. Lcnflct, 8, 926-8 (Mar. 14, 1935).

(49) SILVERMAN, "Easy experiments to be made a t home." ibid., 8, 970 (Mar. 28, 1935).

(50) SmnieloEn, "Projects." ibid., 8, 112W2 (Apr. 18, 1935). (51) K m m r ~ , "Simple demonstration of catalysis," J. GEM.

Eouc., 12, 362 (Aug.. 1935). (52) CALDWELL, "Games for a chemist's party,'! ibid., 12,

393 (Aug.. 1935).

(53) FERGUSON, "Rhombic sulfur crystals," Sci. Leqlet, 9, 215 (Oct. 24, 1935).

(54) DERRICK, "Assembly programs." ibid., 9, 403-6 (Nov. 21, 1935).

(55) SANPOED, "Wood distillation model," J. CHEM. EDUC., 11, 45 (Jan., 1934).

(56) SOLA. "A play for the biology or chemistry club," Sci. Leaflet. 7. 953-6 (Apr. 12, 1934).

(57) HOLMES, "~xperiments with nascent gases," J. CHEM. EDUC.. 11. 308 IMav. 1934). . .

HORMISDAS. "wodd distillati& in the laboratory," ibid.. 11, 479 (Aug., 1934).

FALL, "Our 1933 'chem party,"' Sci. Leefit, 8, 2- (Oct. 25, 1934).

WALRATH, "A student-made chemical balance," J. CHEM. Eouc., 10, 118 (Feb., 1933).

SANPORD. "Electric furnace for calcium carbide prepara- tion." ibid.. 10. 420 (Tulv. 1933). .. . .

(62) HOOTON, " ~ e m o k a t i o n of theSolvay process," ibid., 10, 437 (July, 1933).

(63) WAILES. "Weird stunts with aluminum,'' Popular Sci. Monthly, 123, 5 2 3 (Sept., 1933).

(64) MORRIS AND HEADLEE, "Lecture experiments in general chemistry,'' J. CHEM. EDUC., 10, 637-8 (Oct.. 1933).

(65) HAZLEHURST, "Demonstrating the oxidation of ammonia," ibid.. 10, 639 (Oct., 1933).

(66) BAKER, "Blast lamp from a Bunsen burner," ibid., 10, 745 (Dec.. 1933).

(67) A ~ m m AND KING, "Lecture demonstration of the are process," W., 10, 748 (Dec., 1933).

(68) SmnEaaEn, "Suitable projects in plant chemistry," ibid., 9, 11034 Uune. 1932).

(69) STONE, '*Some experiments with crystals," ibid., 9, 11074 Uune, 1932).

(70) OLSSON, "A demonstration: Fixation of atmospheric nitrogen," ibid., 9, 1829-30 (Oct., 1932).

(71) LISK, "The making of ozone as a laboratory exercise," iW.. 9, 2099 (Dec.. 1932).

(72) BAKER AND PKARES, "A chemistry exhibit," {bid., 9, 501-9 (Mar., 1932).

(73) WEAVER, "Experiments with solid carbon dioxide," Chnt. LcopC1, 6, 379-82 (Dec. 1, 1932).

(74) W U L ~ S , "Fertilizer from the air," J. CHEM. Enuc., 8, -70 (Mar., 1931).

(75) RADEMACHBR, "Making posters for chemistry," ibid., 8, 688-98 (Apr.. 1931).

(76) READ. "Inspection trips," ibid., 8, 919-28 (May, 1931). (77) FINE, "Some spectacular experiments in chemistry,"

ibid.. 8. 929-35 (Mav. 1931). . , . .. (78) Gnlaaom,, "A colored ammonia fountain." &id.. 8, 1059

(June, 1931). (79) CIUIY, "Liquid air," ibid., 8, 102743 (June, 1931). (80) JAMES, "A laboratory reproduction of the viscose process,"

W., 8, 1171-2 Uune, 1931). (81) WHITE. "An inexpensive water-cooled condenser," ibid.. . .

8, 1352 (July, 1931). (82) En-. "A model water softener for clawaom demonstra-

tion." ibid., 8, 1361-6 (July. 1931). (83) MOSELEY, "Applications of the small camera," ibid., 8,

135M3 (July, 1931). (84) PERSING, "A high-xhool course in photography," $id.,

8, 1587-97 (Aug., 1931). (85) LEBOWITZ. "A demonstration working model of the

Frasch process for mining sulfur," ibid., 8, 1630 (Aug., 19311.

(86) HAUB, "A novel high-school experiment in the hydro- genation of oils," ibid., 8, 1856-7 (Sept., 1931).

(87) HERD, "The preparation of liquid ammonia." &id., 8, 206% (Oct., 1931).

(88) JOEDY. "Explo~ives: A burlesque lecture," ibid., 7, 653-9 (Mar.. 1930).

(89) JAMES. "A simple bisulfide spectroscope." ibid., 7, 666 (Mar., 1930).

(90) ~ E R E A C H E R . "The dewlorizing action of carbon," stration," J. C ~ M . Eouc., 7, 166&70 (July, 1930). J. C ~ M . Eouc., 7,1299 Uune, 1930). (96) STONE, "Some experiments in crystallization." ibid., 7,

(91) DENNIS, "TWO models: Frasch and lead chamber," 2170-1 (Sept., 1930). ibid.. 7 , 13&7 (June. 1930). (97) LISK, "Hydrogen ballwns;' dbid.. 7, 2719 (Nov., 1930).

(92) JAMES, "A dance of carbon particles," i6id., 7, 1400-1 (98) C O L E M ~ , "A small electric furnace." a i d . , 7, 2720-1 (June, 1930). (Nov.. 1930).

(93) T m m STARECK, "The growth of lead trees in silica (99) Lnaaan. "The fraternity initiation: A one-act burlesque," gel." ibid.. 7, 152G36 (July, 1930). ibid., 6, 2254-9 (Dec., 1929).

(94) STONE. "Preparation of a synthetic resin;' ibid., 7, 1663 (100) FRANK a m B m o w , "Mystery experiments and proh- (July, 1930). lems," J. 0. Frank. Oshkash, Wis.. 1935. (A small

(95) OELKE,"A chamber sulfuric acid plant for lecture deman- book containing several gwd demonstrations.)

CR203 AS A CATALYST IN KCLO, DECOMPOSITION

MARTIN MEYER

Brooklyn College, Brwklyn, New York

OF ALL the substances which catalyze the thermal decomposition of KClOh Cr20~ seems, from the stand- point of low temperatureand speed of reaction, to be the most efficient. As little as one per cent by weight will work satisfactorily and i t is useless to employ more than five per cent.

The catalytic cycle seems to involve K1Cr207, which functions equally well as a catalyst. Some chlorine is evolved, but as i t is removed in collecting over water, this is no disadvantage.

The familiar student experiment of preparation of

oxygen is better done by the following modifications of the usual directions: To five grams of KCIOs add one crystal of KL!r,07 about the size of the head of a large pin. Heat gently with the usual setup.

The method has these advantages: it proceeds smoothly a t a relatively low temperature and may be stopped at any time by cooling; when all oxygen is evolved the contents of the tube obviously solidify; more KC108 may be added if desired without more catalyst; the test tube is easily washed out with hot water.

FROM THE PRESIDENT OF THE UNITED STATES:

A SIMPLE EXPERIMENT ILLUSTRAT- ING DIFFUSION

(The follauing letter has been mode public by the Federal Security Agency, and we think it important enuugh to JOHN H. GARDNER print in full.) Washington University, Saint Luis, Missouri Mv dear Mr. Administrator:

Reports have reached me that some young people who had planned to enter college this fall, as well as a number of those who attended college last year, are in- tending to interrupt their education a t this time because they feel that it is more patriotic to work in a shipyard, or to enlist in the Army or Navy, than i t is to attend college. Such a decision would be unfortunate.

We must have well-educated and intelligent citizens who have sound judgment in dealing with the di5cult problems of today. We must also have scientists, engineers, economists, and other people with specialized knowledge, to plan and to build for national defense as well as for social and economic progress. Young people should be advised that i t is their patriotic duty to continue the normal course of their education, unless and until they are called, so that they will be well pre- pared for greatest usefulness to their country. They will be promptly notified if they are needed for other patriotic services.

Sincerely yours, FRANKLIN D. ROOSEVBLT

Tm WHITE Houss WASHINGTON

AS A means of rendering diffusion visible to a class of students, a test tube containing solutions of colored salts in a succession of layers has frequently been used. The execution of this experiment requires considerable care and the tube, when prepared, must be carefully protected from agitation if the experiment is to be a success. If gels are used instead of solutions, very much less manipulative skill is required and the finished tube is not affected by agitation in handling. A simple form of such an experiment has been devised.

A test tube is filled to a depth of about five centi- meters with a clear gelatin solution which is allbwed to set to a rigid gel. About an equal amount of the gela- tin solution colored intensely red by the addition of a small crystal of fnchsine is then poured into the tube and allowed to set. The colored gel is then covered with a layer of paraffin to prevent putrefaction. In about an hour a noticeable diffusion of the fuchsine into the colorless layer will have taken place, the pene- tration continuing a t a diminishing rate for several days. At all times, the original line between the colored and colorless layers remains visible.