PYROLIGNEOUS ACID. 



tion of*water, but by entering into chemical 

 union with the fibre. Sulphate of copper and 

 several other metallic salts are similarly effica- 

 cious; but their poisonous nature prevents 

 their employment tn the preservation of arti- 

 cles of food. 



The inhabitants of northern climates avail 

 themselves of freezing to prevent the putrefac- 

 tion of their food, and the supplies of game 

 and other articles in the Russian markets are 

 retained in a frozen state. Our fishmongers 

 resort to the same expedient for the preserva- 

 tion of their unsold fish, which is daily removed 

 to the ice-house, after having been exhibited in 

 their shops ; salmon is packed in ice for the 

 purpose of transport and preservation. See 

 DECOMPOSITION, DRY ROT, FERMENTATION, MA- 

 NURES, ORGANIC CHEMISTRY, &c. 



PYROLIGNEOUS ACID. This term is 

 generally applied to the acid liquor which 

 passes over along with tar and gaseous pro- 

 ducts, when wood is subjected to destructive 

 distillation. This acid liquor is an impure 

 vinegar, from which acetic acid is obtained. 

 It has in its impure state a powerful smoky 

 odour, not unlike that of Westphalia ham. 

 The acid is purified by converting it into ace- 

 tate of soda, and decomposing that salt by 

 means of sulphuric acid. This acetic acid, 

 after distillation, is in a high state of concen- 

 tration ; but it differs from concentrated acetic 

 acid, by being neither combustible nor crystal- 

 lizable. It is usually lowered by the addition 

 of water. If intended for the table or for do- 

 mestic use, as a substitute for other forms of 

 vinegar, it is usually coloured with a little 

 burned sugar. This manufacture of vinegftr 

 is now carried on upon a very large scale, and 

 the greater part of the vinegar used for domes- 

 tic purposes and in the arts, in many of which 

 it is largely consumed, is derived from this 

 source. Ordinary vinegar, besides containing 

 acetic acid and water, contains also sulphate 

 of lime, some ethereal matter, a portion of sul- 

 phuric acid, and a colouring principle. See 

 VINEGAR. 



Q. 



QUAKING GRASS (Briza; named from 

 brizo, to nod, on account of the quaking cha- 

 racter of the spikelets). A genus of grasses of 

 which some species are pretty and interesting, 

 as B. minor, B. rubra, and B. clusii; but the 

 greater portion are mere weeds. The whole 

 are of easy cultivation. Two species are in- 

 digenous to Britain, the smaller quaking grass 

 (B. minor), and the common quaking grass (B. 

 media), pi. 6, n. See BRIZA. 



QUARRY. A pit or drift from which stones, 

 gravel, slates, or some other similar material 

 is raised. 



QUARTER. The fourth part of any thing, 

 as of a carcass. As a term of weight it de- 

 notes the fourth of a hundred weight, or 28 Ibs.; 

 as -a dry measure it signifies the fourth of a 

 chaldron. Quarter is also a measure of grain 

 containing 8 bushels: it is the common mea- 

 sure by which grain is sold in the southern 

 districts of England, especially when in large 

 quantities. 

 936 



QUINOA. 



QUARTZ. A German term, now universally 

 adopted in scientific languages, and commonly 

 applied in mineralogy to the purer varieties of 

 silica, especially to rock crystal. Quartz oc- 

 curs also in beds : it is usually granular, white, 

 sometimes mixed with mica. 



QUICKS. The young sets of the white thorn 

 used in planting hedges. The term is also 

 applied to couch-grass in some places* See 

 QUICKSET. 



QUICKSANDS Are sandy spots of soil 

 which contain water in such a proportion as 

 to form a sort of shaking quag at certain times. 



QUICKSET. A term applied to the white 

 or hawthorn, the sets or young plants of which 

 are raised by the nursery gardeners for sale 

 for this purpose. See FENCE, HAWTHORN, and 

 HEDGE. 



QUINCE (Cydonia). A well-known genus 

 of fruit trees. C. vulgaris is the species gene- 

 rally cultivated for its fruit. It is a native of 

 Candia; but cultivated over most parts of Eu- 

 rope and North America. It belongs to the 

 natural order Pomaces. The fruit, or quince, 

 is of a roundish, somewhat pyriform shape, 

 and contains ovate-pointed, plano-convex seeds, 

 yielding to boiling a large quantity of muci- 

 lage, which is employed in medical practice as 

 a demulcent. The quince will thrive in any 

 soil, and may be multiplied by suckers. C. ja- 

 ponica is one of the handsomest hardy shrubs, 

 producing its beautiful scarlet or white flowers 

 in great abundance. The Portuguese quince 

 is reckoned the best. Quince-marmalade is 

 greatly admired by those who are fond of the 

 fruit, and all good housewives know its value 

 in adding richness of flavour to apple-pie. 



QUINOA, or PERUVIAN RICE (Chenopo- 

 dium quinoa). Humboldt speaks of this plant 

 as one of the few cultivated in the highest and 

 coldest regions of the Ande"s and the Mexican 

 Cordilleras, where it ranks in utility with the 

 potato, Indian corn, and wheat. Whilst young, 

 the leaves are used as spinach, oxalis (sorrel), 

 or common greens, whilst the seeds are boiled 

 in soups and used as a substitute for rice. The 

 plant is an annual, and resembles French spi- 

 nach, or its kindred Lamb's-quarter (Chenopo- 

 dium album), which is so widely diffused 

 throughout the United States. The seedsare 

 small, about the twelfth of an inch in diameter, 

 yellowish-white, flat, resemble those of millet, 

 and are easily pulverized. The plant attains 

 about 3 feet in height, and produces greenish 

 flowers about the 1st of August. Mr. Gideon B. 

 Smith has raised the quinoa at Baltimore, and 

 found it very productive. (Am. Farmer, vol. 13.) 

 There are a great many species of chenopo- 

 dium, many of which are enumerated under 

 the head of goose-foot. Ig Peru, it would 

 seem the quinoa is subjected to a process of 

 scalding or part-boiling, before it is disposed 

 of by the cultivator, whether for the purpose 

 of assisting in its preservation, or to prevent 

 its cultivation in other countries, is not ascer- 

 tained. To this fact may probably be ascribed 

 the failure of all previous attempts to cultivate 

 it. Having, says Mr. Smith, eaten the quinoa, 

 prepared in several ways, we are of course en- 

 abled to speak of its qualities from experience. 

 Gentlemen who have eaten it in Peru, speak 



