their general. During the military operations of 1878–79 Jamrud became a place of considerable importance as the frontier outpost on British territory towards Afghanistan, and it was also the base of operations for a portion of the Tirah campaign in 1897–1898. It is the headquarters of the Khyber Rifles, and the collecting station for the Khyber tolls. Pop. (1901), 1848.
JAMS AND JELLIES. In the article Food Preservation
it is pointed out that concentrated sugar solution inhibits the
growth of organisms and has, therefore, a preservative action.
The preparation of jams and jellies is based upon that fact. All
fresh and succulent fruit contains a large percentage of water,
amounting to at least four-fifths of the whole, and a comparatively
small proportion of sugar, not exceeding as a rule from
10 to 15%. Such fruit is naturally liable to decomposition
unless the greater proportion of the water is removed or the
percentage of sugar is greatly increased. The jams and jellies
of commerce are fruit preserves containing so much added sugar
that the total amount of sugar forms about two-thirds of the
weight of the articles. All ordinary edible fruit can be and is
made into jam. The fruit is sometimes pulped and stoned,
sometimes used whole and unbroken; oranges are sliced or
shredded. For the preparation of jellies only certain fruit is
suitable, namely such as contains a peculiar material which on
boiling becomes dissolved and on cooling solidifies with the
formation of a gelatinous mass. This material, often called
pectin, occurs mainly in comparatively acid fruit like gooseberries,
currants and apples, and is almost absent from strawberries
and raspberries. It is chemically a member of the group
of carbohydrates, is closely allied with vegetable gums abundantly
formed by certain sea-weeds and mosses (agar-agar and
Iceland moss), and is probably a mixture of various pentoses.
Pentoses are devoid of food-value, but, like animal gelatine,
with which they are in no way related, can form vehicles for
food material. Some degree of gelatinization is aimed at also
in jams; hence to such fruits as have no gelatinizing power an
addition of apple or gooseberry juice, or even of Iceland moss or
agar-agar, is made. Animal gelatin is very rarely used.
The art of jam and jelly making was formerly domestic, but has become a very large branch of manufacture. For the production of a thoroughly satisfactory conserve the boiling-down must be carried out very rapidly, so that the natural colour of the fruit shall be little affected. Considerable experience is required to stop at the right point; too short boiling leaves an excess of water, leading to fermentation, while over-concentration promotes crystallization of the sugar. The manufactured product is on that account, as a rule, more uniform and bright than the domestic article. The finish of the boiling is mostly judged by rule of thumb, but in some scientifically conducted factories careful thermometric observation is employed. Formerly jams and jellies consisted of nothing but fruit and sugar; now starch-glucose is frequently used by manufacturers as an ingredient. This permits of the production of a slightly more aqueous and gelatinous product, alleged also to be devoid of crystallizing power, as compared with the home-made article. The addition of starch-glucose is not held to be an adulteration. Aniline colours are very frequently used by manufacturers to enhance the colour, and the effect of an excess of water is sought to be counteracted by the addition of some salicylic acid or other preservative. There has long been, and still exists to some extent, a popular prejudice in favour of sugar obtained from the sugar-cane as compared with that of the sugar-beet. This prejudice is absolutely baseless, and enormous quantities of beet-sugar are used in the boiling of jam. Adulteration in the gross sense, such as a substantial addition of coarse pulp, like that of turnips or mangolds, very rarely occurs; but the pulp of apple and other cheap fruit is often admixed without notice to the purchaser. The use of colouring matters and preservatives is discussed at length in the article Adulteration. (O. H.*)
JANESVILLE, a city and the county-seat of Rock County,
Wisconsin, U.S.A., situated on both sides of the Rock river,
70 m. S.W. of Milwaukee and 90 m. N.W. of Chicago. Pop.
(1900), 13,185, of whom 2409 were foreign-born; (1910
census), 13,894. It is served by the Chicago & North-Western
and the Chicago, Milwaukee & St Paul railways, and by electric
lines connecting with Madison and Beloit, Wis., and Rockford,
Illinois. The Rock river is not commercially navigable at this
point, but furnishes valuable water-power for manufacturing
purposes. The city is picturesquely situated on bluffs above
the river. Janesville is the centre of the tobacco trade of the
state, and has various manufactures. The total value of the
city’s factory product in 1905 was $3,846,038, an increase of
20.8% since 1900. Its public buildings include a city hall,
court house, post office, city hospital and a public library. It
is the seat of a school for the blind, opened as a private institution
in 1849 and taken over by the state in 1850, the first
charitable institution controlled by the state, ranking as one of
the most successful of its kind in the United States. The first
settlement was made here about 1834. Janesville was named
in honour of Henry F. Janes, an early settler, and was chartered
as a city in 1853.
JANET, PAUL (1823–1899), French philosophical writer, was
born in Paris on the 30th of April 1823. He was professor of
moral philosophy at Bourges (1845–1848) and Strassburg (1848–1857),
and of logic at the lycée Louis-le-Grand, Paris (1857–1864).
In 1864 he was appointed to the chair of philosophy at the Sorbonne,
and elected a member of the academy of the moral and
political sciences. He wrote a large number of books and articles
upon philosophy, politics and ethics, on idealistic lines: La
Famille, Histoire de la philosophie dans l’antiquité et dans le
temps moderne, Histoire de la science politique, Philosophie de la
Révolution Française, &c. They are not characterized by much
originality of thought. In philosophy he was a follower of
Victor Cousin, and through him of Hegel. His principal work
in this line, Théorie de la morale, is little more than a somewhat
patronizing reproduction of Kant. He died in October 1899.
JANGIPUR, or Jahangirpur, a town of British India, in Murshidabad district, Bengal, situated on the Bhagirathi. Pop. (1901), 10,921. The town is said to have been founded by
the Mogul emperor Jahangir. During the early years of British
rule it was an important centre of the silk trade, and the site of
one of the East India Company’s commercial residencies. Jangipur
is now best known as the toll station for registering all the
traffic on the Bhagirathi. The number of boats registered
annually is about 10,000.
JANIN, JULES GABRIEL (1804–1874), French critic, was born at St Étienne (Loire) on the 16th of February 1804, and died near Paris on the 19th of June 1874. His father was a lawyer, and he was well educated, first at St Étienne, and then at the lycée Louis-le-Grand in Paris. He betook himself to journalism very early, and worked on the Figaro, the Quotidienne, &c., until in 1830 he became dramatic critic of the Journal des Débats.
Long before this, however, he had made a considerable literary
reputation, for which indeed his strange novel L’Âne mort et la
femme guillotinée (1829) would have sufficed. La Confession
(1830), which followed, was less remarkable in substance but
even more so in style; and in Barnave (1831) he attacked the
Orleans family. From the day, however, when Janin became
the theatrical critic of the Débats, though he continued to write
books indefatigably, he was to most Frenchmen a dramatic
critic and nothing more. He was outrageously inconsistent, and
judged things from no general point of view whatsoever, though
his judgment was usually good-natured. Few journalists have
ever been masters of a more attractive fashion of saying the first
thing that came into their heads. After many years of feuilleton
writing he collected some of his articles in the work called
Histoire de la littérature dramatique en France (1853–1858), which
by no means deserves its title. In 1865 he made his first attempt
upon the Academy, but was not successful till five years later.
Meanwhile he had not been content with his feuilletons, written
persistently about all manner of things. No one was more in
request with the Paris publishers for prefaces, letterpress to
illustrated books and such trifles. He travelled (picking up in
