Cancer: Invention of the Microscope

by National Cancer Institute

(Page 3 of 9)

1683 - 1687

A DUTCH EYEGLASS MAKER, Johannes Jansen, and his son Zacharias are credited with inventing the microscope c.1590 and the telescope in 1608. The Jansen microscope was rapidly put to work by 17th-century researchers throughout Europe who investigated the structures and functions of human organs, as well as plant life and bacteria.

Discovery of the Cell

In his Micrographia (1655), Robert Hooke illustrated tissue structure in plants, calling it "little boxes of cells." His observation of "cells" led to the 19th-century theory of the cell as the basic unit of all living organisms.

Leeuwenhoek's Discoveries

A linen merchant of Delft, Antony van Leeuwenhoek (1632-1723) was a brilliant layman who pursued his hobby of lens-grinding to a place in history as the father of microbiology. Leeuwenhoek produced microscopes with the magnification power of 270 times, and discovered spermatozoa, bacteria and protozoa.

Oncology's Arrival In The "Age of Reason"

1733 - 1788

IDEALS OF POLITICAL AND INTELLECTUAL FREEDOM ignited revolutions on both sides of the Atlantic in the 18th century. Newspapers, magazines and new national museums in France and England spread information to a wider public. Modern pathology was established, and physical diagnosis became more common. With the first systematic experiments in cancer, oncology was born as a medical discipline. Environmental cancers were reported, and hospitals specializing in cancer care were opened.

New Theories: Cancer as a Local Disease

Rejecting the 17th-century theory that cancer was caused by acid ferments, the French physician Claude Gendron (1663-1750) concluded after eight years' research that cancer arises locally as a hard, growing mass, untreatable with drugs, that must be removed with all its "filaments." The Dutch professor Hermann Boerhaave believed inflammation could result in a scirrhus, or tumor, capable of evolving into cancer.

Nuns, Chimney Sweeps and Snuff-Takers: First Observations on Environmental Cancers

A life- or health-threatening environmental hazard was first observed and studied in the 18th-century. Correlations between working conditions and the health of workers were analyzed, as were the carcinogenic effects of using substances such as tobacco products. The connection between certain environments and the onset of cancer was clearly drawn.

Experimental Oncology Begins

Two 18th-century French scientists, physician Jean Astruc and chemist Bernard Peyrilhe, conducted experiments to confirm or disprove hypotheses related to cancer. Their efforts, however absurd they seem in retrospect, established experimental oncology, the science of seeking better diagnoses, treatments and understanding of the causes of cancer.

John Hunter and the Rise of Scientific Surgery

Well-grounded in physiology and anatomy, John Hunter raised surgery from a technique to a science. His greatest achievement was a method of closing off an aneurysm (an arterial bulge), a procedure which often made amputation unnecessary. Hunter taught that if a tumor were moveable, it could be surgically removed, as could resulting cancers in proper reach. If enlarged glands were involved, he advised against surgery.

Prelude to The 20th Century

1800 - 1892

IN SCIENCE, MEDICINE, INDUSTRY AND TECHNOLOGY, the 19th century soared, an essential and spectacular overture to the advances of our time. Darwin published the theory of evolution; Pasteur invented bacteriology and began the fight against infectious diseases; Virchow focused pathology on the cell; and anesthesia and antisepsis improved surgery. A series of remarkable discoveries in the closing years of the 19th century set the stage for 20th-century research in oncology and biomedical sciences. Cancer research accelerated as Röntgen described X rays, the Curies isolated radium, and Müller observed abnormalities of cancer cells.

Preventive Medicine: Jenner and a Vaccination Against Smallpox

Smallpox was widespread and deadly in 18th-century England. Edward Jenner caused a furor in 1798 with his paper on inoculating humans against smallpox with fluid from sores of vaccina, a cattle disease. When his paper was declined by the Royal Society, Jenner published it himself. Thomas Jefferson, Napoleon and the Empress of Russia endorsed Jenner's vaccine, which cut the smallpox death rate to nearly zero where its use was compulsory.

The Development of Morbid Anatomy

The removal of bans against dissection and autopsy paved the way for pioneering work by two great pathologists. Giovanni Morgagni correlated and indexed case histories with autopsy findings, and Matthew Baillie produced the first systematic illustrated pathology textbook based on organs. Cancers of the breast, stomach, rectum, testes, bladder, pancreas and esophagus were described in fine detail in their works.

Through the Microscope: Focusing on Cancer Cells

Better microscopes not only helped apprehend disease-causing organisms, but also made possible the examination of cells and cellular activity. Study of cancer tissues and tumors revealed that cancer cells were markedly different in appearance than normal cells of surrounding tissue. Researchers began to focus on questions such as the origin of cells and the relationship of disease to the behavior of a cell.

Surgery Comes of Age: Antisepsis and Anesthesia

Before Joseph Lister's experiments with disinfectants and Crawford Long's introduction of ether, surgery posed a grave threat of infection and death to patients and the certainty of unbearable pain. Lister's use of carbolic acid sprays in operating rooms and hospital wards sharply lowered mortality rates. Ether anesthesia in general surgery enabled the science of surgery to advance rapidly.

First Cancer Statistics Are Collected

By the mid-19th century, French and Italian researchers had found that women died from cancer much more frequently than men, and that the cancer death rate for both sexes was rising. Using analyses by age, sex and occupation, Domenico Rigoni-Stern concluded that incidences of cancer increase with age; that cancer is found less in the country than in the city; and that unmarried persons are more likely to contract the disease.

Pasteur, Koch and the New Science of Bacteriology

Louis Pasteur's experiments confirmed ancient theories that invisible organisms caused disease, and paved the way for Lister's work in antisepsis. Pasteur identified bacteria responsible for sheep anthrax and chicken colera, and found the cause and cure for rabies. Robert Koch developed bacteria cultures, discovering the tuberculosis bacillus, the cholera vibrio, and the transmission of plague by fleas.

About the Author

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