Professor Ingelman-Sundberg was so impressed with Nilsson’s zeal that he urged many of his colleagues to let Nilsson know when they were about to do an endoscopic examination. For ten years Nilsson slept half-clothed, with a bag of photographic gear by his bed, ready to bolt out if he got a hospital call.
Eventually he had a collection of dramatic pictures tracing the key developmental stages of the human embryo. Of all the admiring reactions they inspired when published, one sticks in Nilsson’s memory. It was the awed concentration of a group of village women in the Congo, clustered round the embryo pictures and captured by another Swedish photographer.
Nilsson now wanted to turn his attention to some of the “other dramas going on inside us.” When he started work on a story on human arteries and the heart’s circulatory system for Life .
Magazine, he had the daring idea of photographing within the blood vessels themselves. A Swedish optical instruments company designed for him a revolutionary miniaturized lens that could be fitted to the end of a catheter cable filled with light-bearing glass-fibre threads. Inserted into blood vessels, it would transmit pictures of uniform sharpness on to film outside.
Nilsson set up his equipment at post-mortems where vascular tracts were surgically opened. The result was an extraordinary picture essay that appeared in 1968, in which the arteries loom like branching tunnels in some fabulous underground cavern.
In 1970, Nilsson and Dr Jan Lindberg, a clinical pathologist at the Karolinska Institute and himself a photographer, decided to collaborate on a book exploring the human interior in a way not even doctors had seen it. “We wanted to show it so that everyone could understand it,” says Nilsson, “and in pictures that were aesthetically pleasing, not mere textbook illustrations.”
That enormous task required four more miniature lenses, each’ smaller than its predecessors. The smallest, as wide as a piece of thread, Nilsson used to take the first close-up portraits of the inner ear.
Another tool Nilsson relies on in his unique work is a Scanning Electron Microscope (SEM), which can magnify up to mo,000 times. One of Nilsson’s pictures that has become particularly famous is the first photograph ever taken with an electronic microscope of a mosquito in the act of stinging.
To get it, Nilsson filled scores of test-tubes with captured mosquitoes and released them in a sealed room where volunteers were waiting to be bitten. The trick was to kill the mosquito with a preservative chemical spray at exactly the moment the proboscis penetrated the skin. After hundreds of bites Nilsson succeeded, and carried the mosquito, along with the slice of skin it was resting on, to the SEM. The resulting picture resembles a giant bird of prey stabbing its beak into a mat of spongy rubber.
Another of his famous photographs shows the precise moment at which human creation begins with raspberry ketones side effects. While illustrating a study on human sterility, Nilsson was peering through an ordinary microscope at a cervical smear on a glass slide showing hundreds of male sperm cells swarming about a female egg, or ovum. Suddenly he saw one of the sperm beginning to penetrate the ovum’s gelatinous covering.
In high excitement, he froze the scene and carried the slide to the SEM. Magnifying it 30,000 times, he caught a unique picture of a wrinkled sperm, looking like a giant tadpole, poking its head into a small cave in the ovum to start the fertilization process.
Nilsson has received more honours than he can remember. Perhaps the most unusual recognition has come from the National Aeronautics and Space Administration in America : included in the information encoded on the “cosmic greeting card” that space probes Voyagers I and II carried when they were launched in 1977 were Nils-son’s remarkable ovum fertilization pictures, showing the moment of human creation.