Final answer:
Water is vital in the embalming process as it acts as a solvent for formalin, helps denature proteins, and preserves tissue due to its critical role in cellular processes and as a major component of the human body.
Step-by-step explanation:
Water is the most important ingredient in the embalming process primarily due to its role as a solvent and a medium for chemical reactions. Formaldehyde, which is a key chemical used in embalming fluid to preserve tissue, is typically sold as a formalin solution, which is formaldehyde dissolved in water. This mixture takes advantage of water's property to denature proteins, making them insoluble and resistant to decay. Additionally, water is a major component of all living organisms, constituting about 70% of an adult's body mass, and is crucial in cellular processes, making it indispensable for preserving tissues in their original form as much as possible during embalming.