VOL. 6. NO. 10
SELP-HELP POR TEACHERS
1733
SELF-HELP FOR TEACHERS C ~ L EH.SSTONE, ENGLISH HIGHSCHOOL, BOSTON, MASSACWSET~S
The live teacher is always seeking to improve in the practice of his profession. He looks continually for new avenues of development, for new ideas in teaching, for new methods of approach to difficult topics, for new demonstration, and laboratory material. As one thus endeavors to grow, it is a joy to find the viewpoint broadening and the grasp upon the subject becoming stronger and more comprehensive. For teachers in the larger centers there are the afternoon, evening, and Saturday courses in various subjects. These and the annual summer school offer the progressive person ample opportunity for development. But there are many teachers in the smaller towns to whom most of the above advantages are not available. Even the summer school is often a formidable proposition, for to the amount of the bill for tuition a t the distant college or university must be added the expense of room and board and the cost of travel which may often he a considerable factor. Unless some or all of these items are provided for by the local board of education (not likely in most cases) many teachers feel that they can ill afford the expense of a summer course. If you are unable to carry on research because of insufficient preparation or inadequate facilities, do not be discouraged. At your very door lies a great opportunity. You can improve yourself if you so desire and do it in your own laboratory. All you need is the $1 to work and an allowance of half an hour a day. Steadily followed, this method will enable you to accomplish much and you will be surprised to find how easily progress is made. This is a statement of fact based upon experience. Let any ambitious teacher select some topic which he wishes to study more in detail in order to acquire a wider knowledge of the subject and more skill in carrying out the work selected. Suppose, for example, you choose glass as your theme. Have you practised glassworking, cutting, firepolishing, bending, sufficiently to feel that you are expert in such work? Have you ever done a really creditable piece of glass etching? Do you know how to silver glass? Can you demonstrate that ordinary glass can be made sufficiently soluble in water to give an alkaline reaction with phenolphthalein? What experimental work have you done with water glass? Another fruitful topic is that of the preparation of compounds of the common metals. Starting with a chunk of malachite ore, could you prepare the various copper salts? Do you know by actual experience how to convert litharge into the numerous oxides and salts of lead? Have you ever prepared such simple substances as sodium nitrite, potassium sulfate, zinc chromate? Have you ever made such compounds as barium chloride, lead nitrate, sodium acetate, and others in 500-gram lots for
laboratory use? Are you familiar enough with the preparation of potassium iodate to direct a student who may desire to make some so that he can do the "wink" experiment? Would you know how to convert copper, which is insoluble in hydrochloric acid, into copper chloride? If you have not done these things, and many others like them, there is a lot of interesting work waiting for you. These preparations provide excellent opportunities for the extension of your knowledge of chemical reactions, and the procedures of solution, filtration, evaporation, and crystallization. The finished products, suitably preserved, may be put in the exhibition case for the edification of your students whose respect for your ability as a chemist will thereby be vastly increased. If the common elements are already sufficiently familiar, there are the less common ones. What work haveyou done with clromium and manganese? Would you know how to convert chromium oxide into potassium chromate? Or the chromate into the dichromate? Have you ever prepared potassium permanganate? What work have you done with uranium compounds or the complex cobalt salts? How are barium ferrate and sodium tetrathionate made? Perhaps organic chemistry may interest you more than inorganic chemistry. Have you prepared a t your school such compounds as ethyl bromide, ethylene bromide, iodoform, acetamide, and others? What work have you done with the aromatic compounds? One needs only a good laboratory manual and a supply of common sense to be able to accomplish E much. If the simpler organic compounds are already familiar, there are the dyes, a most fascinating subject. Such coloring materials as Orange 11, Bismark brown, resorcin green, naphthol yellow S, magenta, eosin, Meldola's blue are not difficultto make. One of my students is already making a series of dyes with good success and this is only his first year of chemistry. The work is therefore not beyond the capacity of any teacher of.ability and determination. Then there are the synthetic resins. Did you ever try to prepare any of them? I t is easy to make a hard, insoluble solid of different colors from phenol and paraform. I do not say that the specimens prepared in my laboratory would pass inspection by the Bakelite chemists, but they are at least interesting and worth making; they provide an avenue of escape into a new field for the teacher who is weary of the tiresome repetitions of simple student experiments in the laboratory. Colloids may interest you. Can you make solid alcohol and explain how it is formed? Do you know how to prepare a ferric sol? What experimental work have you done with rubber latex? How extensive is your knowledge of protective colloids, of Cottrell's process, of cataphoresis? Have you any first-hand experimental knowledge of ore flotation?
VOL.6, No. 10
SELS-HELP FOR TEACHERS
1735
Textiles offer an attractive field for investigation. Can you analyze a sample of goods for wool and cotton? What dyes will not "take" on cotton? Do you understand the principles of union dyeing? What is an assistant, a leveling agent, a mordant? Could you dye three samples of wool yarn three different colors with alizarin? If the electric current is available in your school, what work have you done with electroplating? Have you made white lead, iodoform, canarin, or potassium permanganate by electrolysis? If you are teaching in a rural school, there is the field of agricultural chemistry. Have you tested the soil in the nearby cornfield for phosphates, nitrates, and potassium compounds? Do you know how to make the insecticides: kerosene einulsion, lime-sulfur, Bordeaux mixture, Paris green, lead arsenate? Could you analyze a sample of paint and determine whether its base was zinc or lead? Is the water in your neighborhood temporary or permanent hard water? Is there any starch in an apple, a cucumber, a beet? Have you done the Babcock test for cream in milk? If you teach girls, then you have the field of household chemistry. Can you prepare baking soda by the Solvay process? Can you make good soap? Do you know how to prepare chemically pure salt? Have you tested the various brands of household ammonia for their relative values? Is there any phosphate in Oakite, or carbonate in Lux? When your students know that you are working along advanced lines and see the samples you are frequently putting out, the effectupon them is very stimulating. Some of them may feel t$evurge to go a little deeper into the fascinating realm of chemistry. And as you advance, becoming more and more the master of your selected topics, you will feel a growing sense of power and confidence so that when some bright youngster wants to try work a little beyond that which the others are doing, you are all ready for him and can suggest interesting lines for him to follow as fast as his required experiments are out of the way. The suggestions given above cover only a few of the many possibilities lying ready a t every teacher's door. Get a good handbook of directions, pay out a dollar or two for chemicals not already in the school stock and go to work with a will. You will find the effort well worthwhile and the work fascinating, for you will learn much and enjoy a growing sense of mastery as you proceed.
