Microbiology and Immunology

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AAbbe, Ernst BBE, ERNST(1840-1905)

German optical engineer

Ernst Abbe was among the first optical engineers, designing

and perfecting methods for manufacturing microscopes and

lens systems of high quality. Though he was a great scientist

in his own right, he might have remained anonymous but for

the foresight of his employer, Carl Zeiss (1816–1888). In his

early twenties Abbe was working as a lecturer in Jena,

Germany. He was recognized as being intelligent and industri-

ous, particularly in mathematics, but he was unable to secure

a professorial position at the university. In 1855 Zeiss, the

owner and operator of a local company that built optical

instruments, approached him. Zeiss had realized that the dra-

matic rise in scientific interest and research in Europe would

create a demand for precision instruments—instruments his

shop could easily provide. However, neither Zeiss nor his

employees possessed the scientific knowledge to design such

instruments. Abbe was hired as a consultant to mathematically

design lenses of unrivaled excellence.

The science of lenscrafting had stalled since the time of

Anton van Leeuwenhoek(1632–1723), chiefly due to certain

seemingly insurmountable flaws in man-made lenses.

Foremost among these was the problem of chromatic aberra-

tion, which manifested itself as colored circles around the sub-

ject. Scientists were also frustrated with the poor quality of the

glass used to make lenses. During the following decade, Abbe

worked on new grinding procedures that might correct chro-

matic aberration; by combining his efforts with Zeiss’s glass-

maker, Otto Schott, he eventually succeeded in producing

near-flawless scientific lenses of exceptionally high power.

These same ten years were profitable ones for Abbe. With the

increasing success of the Zeiss Works, Abbe was recognized

as a scientist and was given a professorship at Jena University

in 1875. Zeiss, who realized that the success of his business

was in no small part due to Abbe’s efforts, made the young

professor a partner in 1876. Abbe’s work on theoretical optics

earned him international notoriety, and he was offered a posi-

tion at the prestigious University of Berlin (a position he

declined in order to continue his research at Zeiss).

During their collaboration Abbe and Zeiss produced

thousands of scientific optical instruments. Their innovations

set important standards for the development of telescopes and

photographic equipment. Carl Zeiss died in 1888 leaving the

entire Zeiss Works to Abbe. In addition to running the com-

pany, Abbe used his own considerable funds to set up the Carl

Zeiss Foundation, an organization for the advancement of sci-

ence and social improvement.

See alsoHistory of microbiology; Microscope and microscopy

AAcne, microbial basis ofCNE, MICROBIAL BASIS OF

Acne is a condition that affects the hair follicles. A hair folli-

cle consists of a pore the opens to the surface of the skin. The

pore leads inward to a cavity that is connected to oil glands.

The glands, which are called sebaceous glands, produce oil

(sebum) that lubricates the skin and the hair that grows out of

the cavity. As the hair grows the oil leaves the cavity and

spreads out over the surface of the skin, were it forms a pro-

tective coating. However, in conditions such as acne, the oil

becomes trapped in the cavities of the hair follicles. This accu-

mulation of oil is irritating and so causes an inflammation. One

consequence of the inflammation is an unsightly, scabby

appearing crust on the surface of the skin over the inflamed

follicles. This surface condition is acne.

Acne is associated with the maturation of young adults,

particularly boys. Part of the maturation process involves the

production or altered expression of hormones. In adolescence

certain hormones called androgens are produced. Androgens

stimulate the enlargement of the sebaceous glands and the

resulting production of more oil, to facilitate the manufacture

of more facial hair. In girls, androgen production is greater

around the time of menstruation. Acne often appears in young

women at the time of their monthly menstrual period.

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