July 26, 1999

Dr. Mike Pelletier

Principal Applications Scientist

Kaiser Optical Systems, Inc.

371 Parkland Plaza

P. O. Box 983

Ann Arbor, MI 48106

Dear Mike:

I am sorry that it took me so long to send you these bottles of natural waters that I spoke to you about. The three enclosed Nalgene bottles all contain seawater that has been modified by natural hydrothermal processes. The main dissolved constituents in the waters are sulfate(Raman band at about 960 cm-1) and nitrate (Raman band at about 1045 cm-1).

Please use your immersion probe to analyze these three solutions. In order to avoid the Raman bands of the Nalgene, please pour sufficient solution into a glass beaker and set the beaker on aluminum foil, as we did during our visit to your lab. Use maximum laser power and as long of an integration time as you feel is reasonable. Please let me know what the laser powers and integration times were.

Last Friday I had a chance to see your Raman microprobe system in action again. Alian kindly analyzed some sulfur spherules for me in the marine bacteria that we have been studying with the Monterey group. We unfortunately are having electronic problems with our current multichannel Raman probe.

Thank you for taking the time to analyze these samples. Please telephone me if you have any questions.

Best regards,

Jill Dill Pasteris

Professor of Earth and Planetary Sciences

tel. (314) 935-5434