TIL 



TIL 



which T. vulgaris is cultivated as a 

 well-known aromatic pot-herb of the 

 family Labiatce. It is a perennial, and 

 propagated both by seed and slips : it 

 should be placed in a moderately fer- 

 tile bed in a dry situation. 



THYRSUS, or TIIYRSE. An in- 

 florescence similar to that of the com- 

 mon lilac. 



THYROID GLAND. A gland 

 situated in front of the throat : its 

 office is unknown. 



TIBIA. The largest of the two 

 bones of the fore leg. In entomolo- 

 gy, the fourth joint of tlie leg. 



TICK. A well-known race of in- 

 sects found on grass, decayed wood. 

 dec. : they are easily removed by 

 smoking with tobacco. The sheep 

 tick is destroyed by mercurial or sul- 

 phur ointment, or dipping the sheep 

 into a strong infusion of tobacco. 



TIE. In building, a timber or met- 

 al used to bind together two parts 

 which are liable to separate. 



TILLAGE. " Applied to arable 

 land, the stirring and preparing the 

 surlace of the soil, so as to render it 

 fit for the vegetation of seeds ; its 

 object, also, is the destruction of 

 noxious weeds. 



" The whole art of cultivation con- 

 sists in tillage and manuring, and the 

 profit of the husbandman depends on 

 the perfection of the tillage and the 

 economy of labour in producing the 

 effect. A defect in tillage will cause 

 a creat deficiency in the crops in or- 

 dinary years. To ensure good crops, 

 the soil should be in such a state that 

 the rains and dews may readily be 

 diffused through it, without giving it 

 a wet appearance, or evaporating too 

 rapidly. It requires great knowledge 

 and experience to give any particular 

 soil the exact portion of tillage which 

 is suited to it. A fine garden tilth, 

 as it is called, is the most perfect for 

 light soils which have been long cul- 

 tivated and manured : when they can 

 be brought to such a state, that after 

 continued rains the surface dries 

 without forming a crust, and crum- 

 bles of its own accord, the tillage has 

 been good ; and the deeper this soil 

 is stirred, the more it will produce ; 



but where clay abounds in the soil, 

 which in dry weather can be readily 

 pulverized by crushing the dry clods, 

 and be reduced to the finest powder, 

 too much tillage may do more harm 

 than good. The fine clay is soon 

 converted into mud at the surface by 

 the least rain, because it is not suffi- 

 ciently porous to let the water tiirough 

 it ; it dries into a hard crust, which 

 effectually precludes the access of 

 air, and consequently stops the ve- 

 getation of the seed. It is only by 

 abundant manuring with organic mat- 

 ter that this natural tendency in clays 

 to cohere can be overcome ; and un- 

 til this is eflected, it is best to stir 

 clay soils as deep as possible by 

 means of subsoil ploughs, but they 

 should not be pulverized so that the 

 water cannot run down between tlie 

 lumps and clods, and especially the 

 surface should be left in such a state 

 of roughness that heavy rains cannot 

 cover It with a coat of mud. The 

 clods which are left on the surface 

 imbibe the moisture more gradually, 

 and, in drying, fall to pieces, by which 

 the young plants are invigorated, 

 and, as it were, moulded up. This is 

 particularly the case in winter after a 

 frost, as all clay land farmers are 

 w-ell aware. It is very easily ascer- 

 tained whether a soil will bear much 

 tillage or not. It is only necessary 

 to try some of it in a large pot or 

 box ; make the surface very fine by 

 breaking the clods, then water it 

 abundantly, and let it dry in the sun ; 

 if a crust is formed in drying, tiiat 

 soil will not bear too much harrow- 

 ing and pulverizing, and should be 

 left in a moderately rough state after 

 sowing or drilling the seed ; but if, 

 after it dries, the surface is loose and 

 porous, then the finer the tillage the 

 better the seed will vegetate. The 

 whole depends on the ready admis- 

 sion of air or its exclusion. When 

 grass seeds are sown, the surface 

 sliould be well pulverized ; but this 

 cannot be safely done if the soil is apt 

 to run together when mucii rain falls 

 soon after the seed is sown. Some 

 plants, like beans, will force theii 

 way through a very hard surface ; 



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