Plant physiologist analyzing seeds. Seeds contain tiny quantities of glass compounds with properties similar to the silica glass found in windows. The compounds are formed of water and other materials found in the cells. They prevent the aging of seeds and keep them viable for many years. Analyzing the components of the seeds can help to predict the optimal conditions for maximum longevity. The plant physiologist is using a differential scanning calorimeter to detect phase-changes in the water and lipids (fats) contained within the seeds, and so determine the quantities of glass within the seed. This research was carried out at the US Agricultural Research Service's National Seed Storage Laboratory in Fort Collins, Colorado.