Lemon

Lemons are grown on a large scale in California where 95% of the lemon trees in the United States are found. They are produced chiefly in the coastal region of Southern California in the region adjoining the Pacific Ocean where the climate is mild and equable the year round, which seems to favour continuous flowering and fruit production of the lemon tree. More than three-fourths of the 43,000 acres of bearing lemons are found in five counties of Southern California ; more than one-fourth of the bearing lemon trees in America are in Los Angeles County. In the period 1924-28 the annual production ranged from 5,000,000 to 7,500,000 boxes per annum. This was somewhat in excess of the demand as the average annual consumption of lemons in the United States was only about 5,5oo,000 boxes. Only the best lemons are sent to the market ; the poorer ones being used for manufacturing citric acid, pectin, lemon oil, and other by-products. The two chief varieties of lemons grown in California are the Lisbon, a variety introduced from Portugal, and the Eureka, a variety originated from seed grown in California. Most of the orchards planted recently are of selected strains of the Eureka lemon, which is an early-bearing vigorous variety, almost thorn less and with fruit that is almost free from seed.

Candied lemon peel is usually made in England from a larger variety of the lemon cultivated in Sicily on higher ground than the common kind, from which it is distinguished by its thicker rind and larger size. This kind, known as the Spadaforese lemon, is also allowed to remain on the trees until ripe, and when gathered the fruit is cut in half longitudinally and pickled in brine, before being exported in casks. Before candying the lemons are soaked in fresh water to remove the salt. Of the numerous varieties the wax lemon, the imperial lemon and the Gaeta lemon are con sidered to be the best. Lemons are also imported into England to a less extent from the Riviera of Genoa.

Lemons of ordinary size contain about 2 oz. of juice, of specific gravity 1.039-1.046, yielding on an average 32.5 to 42.53 grains of citric acid per oz. The amount of this acid, according to Stod dart, varies in different seasons, decreasing in lemons kept from Feb. to July, at first slowly and afterwards rapidly, until at the end of that period it is all split up into glucose and carbonic acid —the specific gravity of the juice being in Feb. 1.046, in May 1.041 and in July 1.027, while the fruit is hardly altered in appear ance. Besides citric acid, lemon juice contains 3 to 4% of gum and sugar, albuminoid matters, malic acid and 2.28% of inorganic salts.

The simplest method of preserving lemon juice in small quanti ties for medicinal or domestic use is to keep it covered with a layer of olive or almond oil in a closed vessel furnished with a glass tap, by which the clear liquid may be drawn off as required. Ten per cent of alcohol must be added to lemon juice if it is to be kept. From it are prepared the syrupus limonis (dose 1-2 drachms), which consists of sugar, lemon juice and an alcoholic extract of lemon peel, and also citric acid itself. Lemon juice is practically impure citric acid (q.v.). Lemon juice was largely used on shipboard as a preventive of scurvy; its value being now known to be due to its high content of vitamines.

By the Merchant Shipping Act (1867) every British ship going to other countries where lemon or lime juice cannot be obtained was required to take sufficient to give 1 oz. to every member of the crew daily. Of this juice it requires about 13,00o lemons to yield 1 pipe (108 gallons). Sicilian juice in November yields about 9 oz. of crude citric acid per gallon, but only 6 oz. if the fruit is collected in April. The crude juice was formerly exported to England, and was often adulterated with sea-water, but is now almost entirely replaced by lime juice. A concentrated lemon juice for the manufacture of citric acid is prepared in considerable quan tities, chiefly at Messina and Palermo, by boiling down the crude juice in copper vessels over an open fire until its specific gravity is about 1.239, seven to ten pipes of raw making only one of con centrated lemon juice. "Lemon juice" for use on shipboard is prepared also from the fruits of limes and Bergamot oranges. It

is said to be sometimes adulterated with sulphuric acid on arrival in England.

Essence or Essential Oil of Lemon.

The essential oil contained in the rind of the lemon occurs in commerce as a distinct article. It is manufactured chiefly in Sicily, at Reggio in Calabria, and at Mentone and Nice in France. The small and irregularly shaped fruits are employed while still green, in which state the yield of oil is greater than when they are quite ripe. The best is known as Essence de citron au zeste, or, in the English market, as per fumers' essence of lemon, inferior qualities being distinguished as druggists' essence of lemon. Essence of lemon is chiefly brought from Messina and Palermo. The chief constituent of oil of lemon is the terpene, C1oH1s• The lime, Citrus aurantifolia, is sometimes regarded as a var. of C. medica. It is a native of India, ascending to about 4,000 ft. in the mountains, and occurring as a small, much-branched thorny bush. The small flowers are white, the fruit is small and generally oval, with a thin, light green or lemon-yellow bitter rind, and a very sour, good flavoured juicy pulp. It is extensively culti vated throughout the West Indies, especially in Dominica, Mont serrat and Jamaica and is grown to some extent in the Florida keys and on the mainland of Florida but only in the extreme south as the lime is very subject to injury from winter cold. The plants are grown from seed in nurseries and planted out about 200 to the acre. They begin to bear from about the third year, but full crops are not produced until the trees are six or seven years old. The ripe yellow fruit is gathered as it falls. The fruit is bruised by hand in a funnel-shaped vessel known as an ecuelle, with a hollow stem ; by rolling the fruit on a number of points on the side of the funnel the oil cells in the rind are broken and the oil collects in the hollow stem—this is the essential oil or essence of limes. The fruits are then taken to the mill, sorted, washed and passed through rollers and exposed to two squeezings. Two-thirds of the juice is expressed by the first squeezing, is strained at once and exported as raw juice. The product of the second squeezing, together with the juice extracted by a subsequent squeezing in a press, is strained and evaporated down to make concentrated juice; ten gallons of the raw juice yield one gallon of the concen trated juice. The raw juice is used for preparations of lime juice cordial, the concentrated for manufactures of citric acid.

On some estates citrate of lime is now manufactured in place of concentrated acid. Distilled oil of limes is prepared by distilling the juice, but its value is low in comparison with the expressed oil obtained by hand as described above. Green limes and pickled limes preserved in brine are largely exported to the United States, and more recently green limes have been exported to the United Kingdom. Limalade or preserved limes is an excellent substitute for marmalade.

A spineless form of the lime appeared as a sport in Dominica in 1892, and is now grown there and elsewhere, on a commercial scale. A form with seedless fruits has also recently been obtained in Dominica and Trinidad independently.

The Everglade variety of lime, originated by hybridization in Florida, has a larger proportion of perfect flowers than the ordi nary lime and sets and holds a better crop under the attacks of the wither-tip disease common in the West Indies.

The name lemon is also applied to some other fruits. The Java lemon is the fruit of Citrus javanica, the pear lemon of a variety of C. Limetta, and the pearl lemon of C. margarita. The fruit of a passion flower, Passiflora laurifolza, is sometimes known as the water-lemon, and that of a Berberidaceous plant, Podophyllum peltatum, as the wild lemon. In France and Germany the lemon is known as the citron, and hence much confusion arises concerning the fruits referred to in different works. The essential oil known as oil of cedrat is usually a factitious article instead of being pre pared, as its name implies, from the citron (Fr. cedratier). An essential oil is also prepared from C. Lumia, at Squillace in Calabria, and has an odour like that of bergamot but is not quite so powerful.