FOR 



FOR 



Vacations, or by boiling, to separate the 

 impurities; or after rectification it may 

 be concentrated by frost. 



This has now lost its rank as a separate 

 acid, and it has been shown by Fourcroy 

 and Vauquelin to be a compound of the 

 malic and acetic. 



We have been informed, that it has 

 been employed among quacks as a won- 

 derful remedy for the tooth-ach, by ap- 

 plying it to the tooth with the points of 

 the fore-finger and thumb. 



FORMICA, in natural history, the ant 

 or emmet, a genus of insects of the order 

 Hymenoptera. Feelers four, unequal, 

 with cylindrical articulations, placed at 

 the tip of the lip, which is cylindrical and 

 nearly membranaceous ; antennae filiform; 

 a small erect scale between the thorax 

 and abdomen ; females and neuters arm- 

 ed with a concealed sting ; males and fe- 

 males with wings, but to neuters there 

 are no wings. This is a gregarious and 

 very industrious family, consisting, as the 

 generic character snows, of males, fe- 

 males, and neutrals. The last are well- 

 known insects, who construct the nests 

 or ant-hills, who labour with unremitting 

 assiduity for the support of themselves 

 and the males and females, and who guard 

 with such ferocity the larvx, or what are 

 usually denominated ant's eggs. They 

 wander about all day in search of food or 

 materials for the nest, and assist each 

 other in bringing home what is too heavy 

 or large for such as have attempted it. 

 They bring out of their nest, to expose 

 to the warmth of the sun, the newly hatch- 

 ed larvae, and feed them till they are able 

 to provide for themselves. In the even- 

 ing they consume together whatever has 

 been collected during the day, and do 

 not, as is commonly supposed, lay up any 

 store for the winter. They are very co- 

 veteous of aphides, and are at the same 

 time very careful not to injure them, 

 feeding only on their honey-like excre- 

 ment. In the conduct of the ant towards 

 the aphis, a remarkable degree of intelli- 

 gence is displayed. When the aphis 

 does not readily give out this fluid, the 

 ant applies its mandibles to its abdomen, 

 and by a gentle pressure indicates its 

 wants. Sometimes this tender and'delicate 

 creature is carried home by the ant in 

 considerable numbers, and treated with 

 the most marked attention ; in return it 

 suppliesthat industrious insect with a con- 

 siderable quantity of food, and bears the 

 same relation to it as that useful animal, 

 the cow, does to man. This is exemplified 

 in a yellowish ant not uncommon in Penn- 

 sylvania. (See APHIS.) The ant is ea- 



gerly sought after by the formica-leo, and 

 various birds. Ants feed on animal and 

 vegetable substances, devouring the 

 smaller kinds of insects, caterpillars, &c. 

 as well as fruits of different kinds. The 

 largest of the European ants is the F. her- 

 culanea, or great wood-ant, ofachesnut 

 colour, which is found in dry woods of 

 fir, where it inhabits a large nest or hil- 

 lock, composed of dry vegetable frag- 

 ments, chiefly of fir-leaves: the nest is 

 internally distributed into several paths 

 or tubes, converged towards a central 

 part, and opening externally ; in the cen- 

 tre reside the larvae, which are nursed by 

 neutral ants. When full grown, they en- 

 velop themselves in oval white silken 

 cases, in which they undergo their change 

 into the chrysalis state, and at length 

 emerge in their complete form. About 

 seventy species have been described. 



F. nigra is the common black ant of 

 Europe. The great desire that ants have 

 for animal food has been made use of by 

 anatomists, who when they wish to ob- 

 tain the skeleton of an animal too small 

 or delicate to admit of being prepared in 

 the usual way, dispose the animals in a 

 proper position in a small box, with per- 

 forations in the lid, and deposit it in a 

 large ant-hill, in consequence of which, 

 after a certain time, the whole of the soft- 

 er parts are eaten away by these insects, 

 and the skeleton remains in its proper 

 position. 



F. rufa contains an acid which has un- 

 dergone a chemical analysis, &c. See 

 FORMIC acid. 



FORMULA, or FORMULARY, a rule or 

 model, or certain terms prescribed or de- 

 creed by authority, for the form and ma- 

 ner of an act, instrument, proceeding, or 

 the like. 



FORMULA, in church histor)' and theo- 

 logy, signifies a profession of faith. 



FORMULA, in medicine, imports the con- 

 stitution of medicines, either simple or 

 compound, both with respect to their 

 prescription and consistence. 



FORMULA, a theorem, or general rule, 

 or expression, for resolving certain parti- 

 cular cases of some problem, &.c. So 



is a general formula for the greater 

 of two quantities, whose sum is s and dif- 

 ference d \ and- -is the formula, or 

 general value for the less quantity. Again, 

 ^/dx o;~ is the formula or general value 

 of the ordinate to a circle, whose diame- 

 ter is d and absciss x. 

 FORMULARY, a writing containing 



