Science/Technology dichloromethane containing a known amount of the nonvolatile, internal standard 1-octadiene. This demonstrated that no significant amounts of the hydrocarbons remained in the feathers. The combined extracts were dried and filtered before concentrating under vacuum to yield a concentrated solution of oil residue in a lowboiling solvent. The composition of these mixtures was determined by gas chromatography. Reproducibility of the experiments, and the rinsing procedures, was ±10%. The higher boiling components in an oil spill would be the most difficult to remove. Molecular structure of the components appeared to be of less importance than either the relative molecular weights or the boiling points of the components. The one exception was p-cresol, which was removed quite effectively with water washes alone. The addition of detergents did little to improve the efficiency of p-cresol removal. Clinical trials suggest that the variation in feathers among different species is less significant than other factors in rehabilitating oilsoaked birds. More important are the wash temperature, concentration of surfactants, and the like. The results with snow geese are believed to be representative of the lot. There were some dramatic differences between the efficacy of the various surfactants used on these geese. As a group, shampoos and d i s h w a s h i n g detergents worked well, suggesting that they would be effective in decontaminating birds at risk. One commercial formulation, Dawn dishwashing detergent, was the most effective, even in 2% concentrations. Even in low concentrations, the anionic surfactants were found to suds well but to be le?s effective at removing the oil. The commercial maritime bilge cleaners did rather poorly. This is believed to be due to t h e high amount of nonionic surfactants in these materials. Bryndza says the higher boiling contaminants bind tighter to feathers and are, consequently, more difficult to remove. For extremely high boiling contaminants, a pretreatment to soften the contaminants may be necessary. Although the 16
April 15, 1991 C&EN
group did not investigate its effectiveness in this regard, other studies indicate methyl oleate is an excellent agent in pretreatment. This initial study into the problems of rehabilitating waterfowl dealt with cleaning of feathers only. It did not consider the additional
care needed to protect such areas as eyes and respiratory tracts. Actual cleaning of fowl takes great patience and dedication as well as demonstrably reliable data on the chemistry of detergency. Bryndza's group has made a start to that end. Joseph Haggin
Precollege chemistry kit simulates diffraction The University of Wisconsin's Institute for Chemical Education (ICE) is offering its first kit for precollege chemistry instruction. With the kit, an instructor can simulate several types of diffraction inexpensively and without the need for potentially hazardous equipment. ICE, directed by John W. Moore, was established in 1983 as a center to aid science educators in developing better methods and equipment for teaching chemistry in particular and science in general. The institute provides workshops and evaluation services for precollege teachers, publications to aid them in their work, and, now, the first of a series of demonstration kits. The Optical Transform Kit was developed by an ad hoc committee for solid-state instructional materials, chaired by Wisconsin chemistry professor Arthur B. Ellis. Funding has been provided by the National Science Foundation's directorate for education and human resources. The kit consists of two 35-mm slides—each with eight arrays of
dots—and an optional, battery-powered pocket laser of the type frequently used as a lecture pointer. The dot arrays were drawn with a commercial computer program, and the camera-ready copy was photographed with precision slide film. This technique can be used by individual instructors to generate their own arrays. In use, a slide is held stationary a n d t h e laser b e a m p r o j e c t e d through the slide to a wall or screen. Depending on the portion of the slide being used, various patterns can be projected. The spacings of the projected image can be altered by changing the distance between the laser and slide and/or that between the slide and screen. Knowing these basic dimensions permits estimates of the spacings between the original dots on the slides, more or less as would be done in a conventional diffraction experiment. If a point source of white light is available, it can also be used to illustrate that patterns on the slide might serve as diffraction gratings: Each spot of a diffract i o n p a t t e r n is d i s Optical transform kit persed into the colors of the visible spectrum. If two point sources are available, each of a different color, they can 111 Visible-light laser 35-mm slide be used to show, for example, that shorter Projection wavelengths produce screen smaller diffraction patterns. Other lessons are simulates x-ray diffraction possible also. The kits are being disX-ray tube tributed by ICE at cost. Crystal The slides cost $6.00, High voltage and the laser-pointer an X-ray beam a d d i t i o n a l $100. The Lead screen slides can be purchased Photographic separately from ICE. plate Joseph Haggin
