Aloe vera.

When I asked an old Italian woman with an extensive collection of plants how to grow aloe (Aloe barbadensis), she looked at me with a puzzled expression and said she had never heard of that plant. I pointed out an aloe vera sitting right there on her sunny windowsill, and she said, "Oh, you mean the miracle plant." I thought her description was quaint.

A few days later, I burned my finger pretty severely on a hot iron. As I headed for the refrigerator and the medicine cabinet to find an ice cube and some ointment, my usual remedies, I remembered what the old woman had said about using aloe on burns. Oh well, I thought, she just might know what she's talking about.

I snipped a leaf from the small plant she had potted for me, slit it open, and pressed its gel against my wound. Using a bandage, I attached the leaf to my finger.

For the first few seconds I thought I had made a big mistake. The burn that had been stinging badly before now seemed to catch fire. But as I was about to tear off the aloe and reach for my ice cube, the stinging stopped completely. It was as though I'd never been burned at all. When I removed the aloe, about 24 hours later, I didn't even have a burn mark.

Since then I've used the gel from my aloe plant for insect bites, fever blisters, and minor wounds. It has also been used on other skin problems, such as abrasions, rashes, athlete's foot, acne, eczema, and shingles.

Why does it work? Why aloe gel works is unclear. It may be partly because of its high water content, which enables the affected area to remain moist and sterile without being deprived of air. Its ability to heal damaged tissue may be a result of the complex magnesium compounds that aloe contains.

Whatever its ingredients, the healing properties of aloe vera have been known for centuries. Now modern scientists are exploring aloe's potential for treating some of the most perplexing diseases of our day.

Gerald Bratton, M.D., chairman of the Department of Veterinary Anatomy at Texas A&M University, has coordinated more than a dozen research studies on the effect of acemannan (the active ingredient of the aloe vera plant) in treating cancerous tumors in mice. This research is too new to be conclusive, but preliminary results are encouraging. "When I first started working with aloe, they told me it was a panacea for everything you could imagine and I thought they were full of baloney. But my colleagues and I have done enough experimental work now that there's no question in my mind that there's something about the aloe vera plant and the substance that comes from it that does stimulate or change the immune system."

The aloe plant's immune-stimulating property has prompted some researchers to investigate whether it may be effective in treating AIDS. AIDS, or acquired immune deficiency syndrome, is caused by a virus that destroys the body's ability to fight off infection. Laboratory tests conducted at the University of Texas Southwestern Medical Center show that acemannan enhances the immune system's ability to defend itself, although how it does so remains uncertain.

In tests, lymphocytes from people of different blood types were mixed together and acemannan was added. Lymphocytes are white blood cells that respond to invaders (antigens) in the body. The purpose of the tests was to see if the acemannan would increase the lymphocyte reaction to the antigens (in this case, the foreign blood cells). It did, and the researchers concluded that "acemannan, the active ingredient of the aloe vera plant, is an important immunoenhancer."

Subsequent research presented at the Fourth International Conference on AIDS in Stockholm, Sweden, showed that acemannan also stimulates the body's killer T-cells, which attack and destroy virally infected cells within our body.

Carrington Industries, the company that markets acemannan under the name Carrisyn, has tested the drug on AIDS patients in Belgium, and has received approval from the Food and Drug Administration to begin tests on AIDS patients in the United States.

Be careful what you buy. If you are tempted to bring the ancient miracle of aloe vera into your home, be careful what you buy. You will find many products at the drugstore that contain aloe, but most contain too little to do much good.

If your thumb is a little bit green, buy an aloe vera plant; it's one of the easiest plants to grow. It looks like a cactus, but it is actually a succulent of the lily family. Plant it indoors in a pot on a windowsill in colder climates or outdoors in warmer areas. The plant needs very little light and water, and in the wintertime it can go several months without either.

Just be sure that you plant aloe vera (A. barbadensis). Other aloe plants, like the lace aloe (A. aristata), are purely decorative and have no known medicinal properties.