a county of England, which derives its name from its situation amidst the three kingdoms of the East, West, and South Saxons. It is bounded on the north by Hertfordshire; on the south by the river Thames, which divides it from Surrey; on the west by the river Colne, which separates it from Buckinghamshire; and on the east by the river Lea, which divides it from Essex. It extends about 23 miles in length, but hardly 14 in breadth, and is not more than 115 in circumference; but it comprehends the two vast cities of London and Westminster, which are situated in the south-east part of the country, it is by far the wealthiest and most populous county in England. It is divided into 602 liberties, containing 220 parishes, besides a vast number of chapels of ease, and 5 market towns, exclusive of the cities of London and Westminster. The air is very pleasant and healthy, to which a fine gravelly soil does not a little contribute. The soil produces plenty of corn, and the county abounds with fertile meadows and gardeners grounds. In a word, the greater part of the county is so prodigiously afflited by the rich compost from London, that the whole of the cultivated part may be considered as a garden. The natural productions are cattle, corn, and fruit; but its manufactures are too many to be enumerated here, there being hardly a single manufacture practised in Great Britain but what is also established in this county.—Though London is the chief city, Brentford is the county town where the members of parliament are elected. It contains 77,712 houses, inhabited by 130,742 families, containing 349,958 males, and 294,371 females, so that the whole amount of its population is 635,329 persons.

Middlesex is also the name of four different counties in the United States of America; one of them is in Massachusetts, another in Connecticut, a third in New Jersey, and the fourth in Virginia.