Most of the damage in freezing comes from the increasing concentration of salts as cell water is crystalized. This damage can be avoided if the temperature is lowered quickly enough, putting tissues in a non-crystalline solidified state in which water does not separate out as ice. Worms the thickness of a hair have been dipped in liquid air and revived when warmed quickly. But for larger animals, current techniques cannot cause cooling quickly enough.

If technical difficulties can be surmounted, doctors will be faced with a new set of tough decisions with incredible possible complications. In The Homan Agenda, Dr. Roderic Gorney speculates on one theoretical case:

"Obviously there is little point in waiting for a young woman to die of exhaustion from a spreading cancer if you hope to freeze and revive her after means of curing cancer have been developed which will allow her to live out her full lifespan. The best chance of success would come from preserving her while she is still in good general health. But would a patient be committing suicide by deliberately entering a frozen state while well? Or would a doctor be committing murder by processing her under these conditions? There would be no way to know in advance whether while frozen she was really in a state of suspended animation or just postponed putrefaction. If she failed to revive when thawed a century later, the question of the doctor's liability by then likely would be moot, unless he too had been frozen successfully and subsequently revived. Suppose no cure had been discovered yet for his ailment, could he be brought back nevertheless ahead of time and made to stand trial? If he were able to show at his trial that the prosecution knew she died from causes unrelated to her suspension, could the prematurely thawed sick doctor then sue for malicious melting?"

The problems of cultural shock are more likely. Revived and cured patients will find themselves unemployable, without friends--a museum piece from an ancient century. Clearly, there are several things to be considered before the headlong pursuit of immortality is begun in this direction.

Techniques for preserving the brain will probably be developed before similar procedures for an entire human. Already, physiologists have succeeded in preserving a cat's brain and reviving it, getting normal activity as measured by an EEG. Development of techniques for making contact with a free-floating brain are a long way off, but even the idea of research in this field is right out of a science fiction movie. How is a new home to be chosen for a preserved brain? What if it is unhappy in its new abode? It would be all to easy to forget that a preserved brain is not an "it"--the mass of nerves is the essence of a living human being.

FOR MOST PEOPLE the most significant scientific advancements will be those that will fight the symptons of aging, that will push life expentancy back even further. Several illnesses associated with growing old are simply hormone deficiencies, independent completely of the passage of time. Much of aging is thought to be due to connective tissues losing their ability to transmit nutrients and wastes, thus starving and poisoning the cell simultaneously. Doctors are searching for a chemical formulation that will permit these tissues to function indefinitely.

This would leave as a primary cause of death the failure of certain cells which seem to have a programmed time before self-destruction, such as brain and heart cells. In humans, the upper limit is thought to be between 80 and 90 years, a time genetically determined with few variations. But it is theorized that radiation, minor illnesses, and even emotional scars--factors difficult to control--shorten our allotted times.

Longevity itself is a new experience for mankind. Nearly a quarter of all people who have lived to age 65 are alive today, and society has not yet learned how to make that phase of life attractive. The present methods of segregating the elderly in "retirement villages" for lives without content or use creates an economic and psychological burden, especially for those merely waiting to die. The image of the prolonged agony of artifical support for an already lost life has many speaking of a vague right called "death with dignity." Humanity has yet to learn how to grow old gracefully.

The prospectus for mortality is so complex, so incredible, that wary speculators are calling for caution before some of man's new powers are applied. But social "wisdom" has hindered scientific inquisitiveness before. Two million Americans dying annually, many willing to pay anything to continue living, it is doubtful that research into methods to postpone death will be curbed.