stood. Though sometimes it can deal effectively with tumors, at other times it is easily overwhelmed. The fibrin cocoon, if a general phenomenon, might be how a tumor seals itself off from the immune system, allowing no leakage of antigens to stimulate im­mune cells nor any entry of immune cells that rove nearby.

The cocoon does not always suc­ceed. For example, some tumor cells first grew in guinea pigs, but later succumbed and regressed, the Boston group finds. The failure apparently emanated from injuries in tiny blood vessels supplying the tumor.

The blood-supply network is a crucial factor in tumor develop­ment—and might represent another way tumor cells use the cocoon to capitalize on their host's biochemis­try. Fibrin, either by itself (implanted surgically) or as part of the meshwork around tumor cells, stimulates blood vessel development, the Boston sci­entists find. Thus the cocoon may contribute to the future success of the tumor, not only by protecting it, but also by building blood vessels to bring in nutrients. At other times, the fibrin may outdo itself, clogging the tiny vessels so that the developing tumor is choked off and again vulnerable to the host's defense.

The Boston scientists have pub­lished their findings about guinea pigs in the Journal of the National Can­cer Institute (June 6, page 1459). Meanwhile, preliminary experiments show that similar cocoons surround developing tumors in other animals, and possibly in man. D

Revlon agrees to acquire Technicon Revlon, the big cosmetics manufac­turer, and Technicon, a pioneer in blood autoanalyzers, have signed an agreement in principle to combine the two companies. Besides autoanalyz­ers, Technicon makes instruments and systems for analysis of blood, serum, foods, pharmaceuticals, and water pollutants.

Under terms of the agreement, Revlon will offer a new class of 67/s% convertible preferred stock at the rate of 0.6 share for each share of Techni­con stock outstanding. Public share­holders of Technicon also will have the option of taking $18 per share in cash. Each share of the new Revlon stock would be convertible into one half of a share of Revlon common stock.

The entire package will be worth about $400 million. However, only about 15% of Technicon stock is held by public stockholders. The bulk of

the stock, about 85%, is owned by E. C. Whitehead, chairman of the board and chief executive officer of Tech­nicon. Thus, if all of the public stockholders elect to take the cash offer by Revlon, the total cash outlay by the company will be about $50 million.

The fit between Technicon and Revlon is not so farfetched as it might seem. Revlon, which is thought of primarily as a cosmetics company, has been diversifying into health-related areas. Besides USV Pharma­ceuticals, which Revlon acquired in 1966, and Armour Pharmaceuticals, acquired in 1977, the company also owns National Health Laboratories, which has clinical diagnostic labora­tories in 13 cities as well as satellite labs in other cities.

Revlon also acquired Plasma Alli­ance Inc., and Blood Alliance Inc., which operate plasmapheresis centers

DOE studying various w< A wide array of techniques for storing energy is under development at the Department of Energy. Speaking last week in Boston at the 14th Interso-ciety Energy Conversion Engineering Conference, James W. Swisher of DOE's thermal and mechanical en­ergy storage program described sev­eral of the technologies that are likely to reach some stage of commercial development in the next five years.

A storage method for large electric power plants that is already in use in Europe and can be expected shortly in the U.S. is compressed-air storage in underground cavities.

In this system, electrical energy at off-peak periods is used to compress air, which is stored in underground caverns. When needed, the air is re­leased through a turbine, recovering, in state-of-the-art systems, about 55% of the energy required to compress the air initially.

One commercial power plant in West Germany already is using this type of energy storage for supplying power for peak loading periods, Swisher says. Current U.S. research aims primarily at increasing the effi­ciency of the process by eliminating the need for oil-burning compressors to compress the air.

A second technology that already is on the market in a limited way and may soon grow more important is the use of latent heat storage in refractory bricks. Home-sized units using this technology are being sold commer­cially (without government subsidy) in Vermont and Maine, Swisher says.

In these systems, bricks are heated to temperatures as high as 1200° F at

for the collection of plasmas used in the manufacture of blood fractions. Another acquisition, Meloy Labora­tories, makes and markets immu-nodiagnostic reagents.

According to M. C. Bergerac, chairman of the board and chief ex­ecutive officer of Revlon, Technicon will continue to operate as a separate entity under the Technicon name. Existing management and personnel will remain, and the company will continue to be headquartered in Tarrytown, N.Y.

According to Bergerac and White­head, the deal is subject to approval by the boards of directors of the two companies and by their stockholders. Reaction on Wall Street has been fa­vorable for both companies, with an increase in both's stock prices. Technicon's stock already has more than doubled since last fall, in part on merger expectations. D

(s to store energy night, when electricity is relatively cheap. The bricks give up this heat in the daytime, warming the house. The systems are very energy efficient, with more than 90% recovery of the stored energy.

In regions where this technology already is being marketed, the cost of extra equipment that the system re­quires can be recovered in lower electricity costs in about three years. However, such savings require an electricity rate structure in which off-peak electrical use is cheaper than peak use—a structure not in effect in many parts of the country, Swisher says.

Currently at the demonstration stage is a system of seasonal heat storage in natural aquifers. In such a system solar or industrial process heat would be used to heat groundwater in the summer. The water then would be pumped back into the ground to be recovered the following winter for use in space heating or industry.

Tests done by Auburn University scientists at a site near Birmingham, Ala., find that natural water heated to 170° F can be recovered five months later at 120° F, for about 70% energy recovery.

DOE is planning a major demon­stration of this system for cooling, rather than heating, at New York City's Kennedy Airport. In this test, planned for 1983, water will be cooled in the winter and used the following summer to air-condition the airport buildings. DOE also plans, within the next six months, to award six to eight other contracts for demonstration projects using this technology, Swisher says. Π

6 C&EN Aug. 13, 1979