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ALLOWANCE (from "allow,' derived through 0. Fr. alouer from the two See also: action of allowing, or the thing allowed; particularly, a certain limited See also: apportionment of See also: money or See also: food and See also: diet (see See also: DIETARY)
.
In commercial usage "allowance" signifies the deduction made from the See also: gross See also: weight of goods to make up for the weight of the box or package, waste, breakages, &c
.
Allowance, which is customary in most See also: industries, varies according to the See also: trade, See also: district or country; e.g. in the See also: coal trade it is customary for the See also: merchant to receive from the pit 21 cwts. of coal for every ton See also: purchased by him, the difference of 1 cwt. being the allowance for the purpose of making See also: good the waste caused through transhipment, screening and cartage (see TARE AND TRET.)
ALLO%AN, or MESOXALYL See also: UREA, C4H2N204 or
CO/NH– C0NCO. an oxidation product of uric acid, being \NH—CO/
obtained from it by the action of cold nitric acid, C5H4N403 + See also: H2O + 0= C4H2N204 + CO(See also: NH2)2
.
It crystallizes from See also: water in colourless rhombic prisms, containing four molecules of water of See also: crystallization, and possesses a very acid reaction
.
It serves as the starting-point for the preparation of many related substances
.
See also: Zinc and hydrochloric acid in the cold convert it into See also: alloxantin (q.v.), See also: hydroxylamine gives nitroso-barbituric acid, C4H2N203: NOH, baryta water gives alloxanic acid, C4H4N205, hot dilute nitric acid oxidizes it to parabanic acid (q.v.), hot potassium hydroxide solution hydrolyses it to urea and mesoxalic acid (q.v.) and zinc and hot hydrochloric acid convert it into dialuric acid, C4H4N204
.
M
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Nencki has shown that alloxan combines with thiourea in alcoholic solution, in the presence of See also: sulphur dioxide to See also: form pseudothiouric acid, C5H6N4SO3
.
Methyl and dimethylalloxans are also known, the former being obtained on oxidation of methyl uric acid, and the latter on oxidation of caffeine (q.v.)
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