It must have seemed rather fantastic back in the fifties, when Russell Steere froze chunks of plant viruses (tobacco mosaic virus, tobacco nngspot virus, and squash mosaic virus) in drops of water, planed them freehand with a scalpel blade, made a replica of the surface, and examined the replica in a transmission electron microscope. But that was the birth of freeze-fracture and freeze-etch methodology that yielded enormous amounts of information about the morphology of membranes.

There has been a tremendous expansion in the use of video in microscopy in recent years. This is probably not due to the most obvious advantage of video, that of real-time imaging of moving events, but to its use in image analysis systems. The cheapness of PCs and the associated hardware and software to store and manipulate images, coupled with the availability of lowcost CCD cameras has made the analysis of microscope images commonplace. In the article the equipment used and the sorts of analysis which can be performed will be briefly outlined. The standard text on video is that of Inoue; a more recent review is by Weiss et al. while the major video equipment manufacturers will also provide literature and advice on the more up-todate equipment.

LaB6 and CeB6 cathodes are widely used as high-brightness, highstability, long-lifetime cathodes in a variety of electron beam appiications. Two of these factors - stability and lifetime - are critically dependent on proper cathode-mounting design.

When the benefits of LaB6 as an emitter material were first investigated, the LaB6 was indirectly heated by an electron bombardment coil. This design was cumbersome and did not perform well. Wire mounts, such as those used for tungsten emitters, were developed (and are stili used today); however, they have many drawbacks. Their stability and lifetime are limited because the thin wire mount moves easily and will eventually break under the changing temperature conditions encountered during operation.

Last months issue of this publication contained the second article article in this series on digital imaging far TEM - and listed factors that may be stimulating the recent interest in digilal imaging for TEM. Most of the factors are concerned with issues of functionality. A digital imaging system can enhance TEM operation, image storage, image processing and communication. Significantly, the surge in interest was not linked to claims that digital images have better detail than images captured using sheet film. This is a pivotal issue for some microscopists. Nevertheless, my experience has been that many rnicroscopists, even skeptical microscopists, are surprised at the quality of output from a modern digital imaging system when using a high quality output device to produce hard copy images.

We report here on the first year of development of a novel teaching facility which incorporates new techniques designed to reach new audiences without diluting subject content. Interactive computer software coupled with rich scientific content of microscopic images provides a unique opportunity to help students learn science and technology, the laboratory is comprised of twenty student workstations networked to various microscopes, thus expanding the number of students capable of "hands-on" data acquisition and analysis by twenty times. Two scanning electron microscopes (SEM), a transmission electron microscope (TEM), and several light microscopes (LM) are interfaced through a server to the workstations.

Over the years a number of methods have been described to mount tissue sections on glass slides (for example see Humason 1979). This paper presents a novel mounting medium that is inexpensive and readily available at the nearest grocery store - floor polish. This floor polish is available under a variety of trade names (e.g., Brite® and Future® both from S.C. Johnson and Son. Racine, WI) labeled for use with "no-wax" floors. It has been found that this product is well suited to use as a mounting medium for both gelatin/albumin embedded sections as well as epoxy sections. The floor polish has demonstrated a much lesser degree of tissue distortion in some tissues as compared to the mounting media previously used in our laboratory, including Permount® (Fisher Chemical, Fair Lawn, NJ) and 30% sucrose in distilled H2O.

In high resolution imaging of biologic structure, atomic lorce microscopy (AFM) has been prevailing over scanning tunneling microscopy (STM). This is primarily because biologic materials do not conduct electricity, and STM requires that electrons flow to or from the surface of the specimen, whereas electron flow is not required for AFM. Microscopists intent on using STM have compensated by coating specimens with a thin coat of metal. However, the presence of metal atoms on the surface degrades the resolution. A new development may make STM more useful to biologists than ever before.

We are always trying to extend our vision through the four senses of sight, sound, touch and smeil. The microscopy devised by Hooke and Van Leeuwenhoek more than three centuries ago are examples of methods used to extend our visible vision, in fact, instrument designers since then have constructed microscopes using each one of our senses to give us peeks into the microworid. When Robert Hooke took some scrapings from his teeth and viewed the bacteria in these scrapings in his primitive microscope,1 a whole new view of the world ensued. It would, however, have been difficult to predict how microscopy would evolve in the following centuries.

In 1355, or close thereto, a 3-foot wide and 14-foot long linen cloth suddenly appeared in history. Greeted rapturously by millions of Christians, it has maintained its acceptance as the true Shroud of Christ from 1300 years earlier. In 1978, a group of about 30 U.S. scientists and engineers studied the Shroud in great detail. All but one concluded the cloth is the burial Shroud of Christ.