From The Pictorial Encyclopedia of Fashion, Kybalova and Herbenova, Crown Publishers, 1968
This garment [underclothing], basic for both men and women, was straight cut, usually knee length, and had the elbow length sleeves set straight into the shoulders. The women wore their shifts under their corsets, and in the second half of the 17th and 18th centuries the frills at the low cut neckline at at the elbow were intended to show in the openings of the dress. Most was of white linen, easily washable. There was little change in cut or material until the last quarter of the 19th century....
Chemise (French = shirt)Since the Rococco period this has been the term for an under garment with short sleeves; somewhat later (1785-1800) the shirt type garment, the chemise, was the fashion. The name was transferred to a day dress of similar cut.
Dressing Gown, Undress Gown, Nightgown, Neglige Term for a comfortably house garment. In the 17th and 18th centuries it was known as a nightgown and worn by both sexes as in informal house-dress. It was orignally based on the Far Eastern kimono or banyan. Men's dressing gowns preserved their classical style; they were made of silk or flannel and reached to the calves. They were worn for morning toilette, including breakfast. Women's dressing gowns were mostly long, so that they covered the length of the nightdress; in recent times they have also become short or of three-quarter length.
Nightshirt It was first found in the late Middle Ages under the term bedshirt; until then people had either slept naked or had kept on their day clothes. The first nightshirts were very capacious, otherwise they were by and large similar to a day shirt. In general the nightshirt prevailed first in the 19th century, in many countries later. Women often wore at night a night jacket over the day chemise.
Two descriptions from Four Hundred Years of Fashion, a catalogue from the Victoria & Albert Museum. (Hey, I was in London!)
Shift, fine linen English, mid 18th century - The shift has a low, round neck and straight-cut sleeves, set with a gore beneath. They are elbow length, gathered and pleated into an arm-band with worked eyelet holes. The shift reaches to below the knees and is flared in the front and with triangular gores inserted at each side of the back. "4 SH" is worked in red cross-stitch in the centre of the neck.
There are cotton frills at the low, round neck and the short, gathered sleeves. The shift is cut straight and is knee-length with gores at the bust. It is inscribed "1835"
From English Women's Clothing in the Nineteenth Century. C. Willet Cunnington, Dover Books.
During most of the century the underclothing, although varying from epoch to epoch, displayed a persistent feature; it was curiously plain in design and material, even when immense pains were being taken over the dress. Only those portions of undergarments which were likely to be seen received any ornamentation. Thus, the hem of the petticoat would be elaborately embroidered while the chemise would be entirely unadorned; and it was common for the stocking to be beautifully worked on the ankle with the rest quite plain... Underclothing was for the most part inherited from preceding centuries...
dated 1825 of linen. Wide front opening with cambric frill edging; a shallow collar. The sleeves, set in with gussets, are long, finished with a gauged cuff edged with a frill and fastened with one button. The hem is four feet wide.