Page 6 - An Inky Lead Questioned Documents

NOTES

 Choosing good relative characters during the handwriting analysis is essential for the successful
completion of the lab. Make certain that the difference between relative characters and absolute
characters is well understood. You may wish to brainstorm good relative characters as a class
before measuring begins.

 Glass microscope slides are recommended for use as a base plate when working with the
solvent mixture. The solvent contains acetone, therefore plastics should be avoided. Glass petri
dishes also work well.

 While dissolving the ink from the paper, make certain that students are careful not to
contaminate their samples with ink from neighboring numbers. You may wish to have students
circle each number with a wax pencil to prevent the solvent from spreading, otherwise, simply
make certain that sufficient room is left between numbers and that only one or two drops of
solvent are used per number.

 When running the TLC plates, there will be approximately ten to fifteen minutes of down time. It
isrecommended that the lab area be cleaned and the data collection sheet filled in during this
time.

6 THE MYSTERY OF LYLE AND LOUISE