-170
JOURNAL O F CHEMICAL EDUCATION
MARCH,1931
TO-use calcium chloride as a drying agent. To use plaster of Paris and learn why i t "sets." To attach batteries in series so as to get the sum of their voltages and the amperage of one, rather than the sum of their amperages. To use a nitrate fertilizer. To calculate the amount of fertilizer to use on a given amount of seed. To learn how the growth of a plant depends upon fixed nitrogen. To make an acid from a non-metallic oxide and water. To calculate the equivalent amount of nitric acid formed from the weight of calcium nitrate obtained. To make a carbonate by metathesis (making the calcium carbonate from calcium chloride and sodium carbonate). Literature Cited (I) WILLIAMS,"A Working Model By-Product Coke Plant.
A Chemistry Project for a Student a t the Secondary Level," J. CHEM.EDUC.,6, i45-52 (APT., 1929); "From Corn to Karo,"ibid., 7, 1147-53 (May, 1930). "A Course in 2 ) The reactions given are taken from M c P ~ s n s o wand HENDERSON, General Chemistry," Ginn & Co., Boston, Mass., 1915.
Ozone Preserves Color of Red Peppers. When is a red pepper not a red pepper? When i t is faded, of course. The Basic Science Research Laboratory of the University of Cincinnati has discovered that if red peppers are kept in a dark and damp place, and given daily doses of ozone, they will not bleach. In the past there has been considerable loss due t o the bleaching of the color from red peppers while they were in storage. Shortly after the beginning of the investigation, the scientists found that the red pigment that colors the peppers was sensitive to the effects of light. The stronger the light, the more rapidly the color bleached. Not long after this, they found that pcppers kept carefully dry, bleached more quickly than the others. The remedy then seemed ohvious-store them in a dark, damp chamber. But every one knows what happens when food is kept in a damp place. I t molds. They found that several varieties of the common aspergillis mold grew on the damp red peppers. Now a number of chemicals will readily prevent the formation of these molds, but most of them are either unsuitable for use on foods, or else they bleach the red peppers in the presence of moisture. At last ozone was tried, and it was found to he successful. I t killed the mold without bleaching the red peppers, although earlier experiments with omne had indicated that it would bleach them if they were dry. Perhaps the most surprising thing of all is the small quantity of ozone actually required. One-tenth of one per cent for a period of ten minutes a day is enough t o preserve the ruddy appearance of the peppers. A ~.~ a r e n t the l v bleachinn of the red peppers occurs when the skin of the prppers dries out andcracks. Then theair and light reach the delicate inner tissues of the peppers is stored, and bleach them. Thus i t is actually the darkness and where the red uiement .moisture that prevent the bleaching of the color in the peppers, while the ozone merely serves to stop the mold from growing on them.-Science Service
.
