648 



TAN 



THE UNIVERSAL HERBAL; 



tAN 



parts of England do not grind the bark to reduce it into 

 small pieces, as is commonly practised by the tanners near 

 London, where there is a great difference ia the size of the 

 bark, some being ground much smaller than the other, accord- 

 ing to the different purposes for which it is intended ; but vn 

 many places the bark is only chopped into large pieces, 

 which renders it very different for the use of hot-beds ; for if 

 the tan be very coarse, it will require a longer time to ferment 

 than the small tan; but when it begins to heat, will acquire 

 a much greater degree, and will retain the heat a much longer 

 time than the small ; therefore, when there is choice, the 

 middling-sized tan should be preferred, for it is very difficult 

 to manage a hot-bed made of the largest tan ; the heat of 

 which is often so great as to injure the roots of plants that 

 are fully plnnged into the beds. Therefore, where the per- 

 sons who have the care "Of these beds do' not diligently 

 observe their working, they 'may in a short time destroy the 

 plants : on the other hand, if the tan be very small, it will 

 not retain the heat above a month or six weeks, and will be 

 rotten, and unfit for a hot-bed, in a short time. The tan 

 should always be such as has been newly taken out of the 

 pits, for if it lies long in the tanner's yard before it is used, 

 the beds seldom acquire a proper degree of heat, nor do they 

 continue their heat long; so that when it has been more than 

 a fortnight or three weeks out of the pit, it is not so good 

 for use as that which is new. If the tan be very wet, it will 

 be proper to spread it abroad for two or three days, to drain 

 out the moisture, especially if it be in the autumn or winter 

 season, because then, as there will be little sun to draw 

 a warmth into the tan, the moisture will prevent the fermen- 

 tation, and the beds will 'remain cold ; but in summer there 

 is no great danger from the moisture of the tan. The heat 

 of the Sun through the g'lasscs will then be so great as soon 

 to cause a fermentation in the tan. The tan-beds should be 

 always made in pits, having brick-walls round them, and a 

 brick pavement at the 'bottom, to prevent the earth from mix- 

 ing with the tan, which will prevent the tan from heating. 

 These pits must not be less than three feet deep, and six feet 

 in width, but seven is better: the length must be in propor- 

 tion to the number of plants they are to contain, but if less 

 than ten feet in length, they will not retain their heat long; 

 for where there is not a good body of tan, the outside of the 

 bed will soon 'lose its heat, and the plants there plunged will 

 have no benefit of the warmth, nor will the middle of these 

 beds retain their heat so long; hence they will not answer 

 the purpose for which they were intended. When the tan is 

 put into the bed, it must not be beaten or trodden down too 

 close, for that will cause it to adhere, and form one solid 

 lump, so that it will not acquire a proper heat ; nor should it 

 be trodden down at the time when the pots are plunged into 

 the beds, to avoid which there should be a board laid across 

 the bed, and supported at each end, to prevent its resting 

 upon the tan, and upon this board the person who plunges 

 the pots into the tan should stand. When the tan is quite 

 fresh, and has not been out of the pits long enough to acquire 

 a heat, the beds will require a forthight, or 'Sometimes three 

 weeks, before they wrll ; be of a -proper temperature of warmth 

 to receive the plaitt's ; but in order to ascertain this, there 

 should be three or four sticks thrust down into the tan, 

 about eighteen inches deep, in different parts of the bed, 

 that by drawing out the sticks, and feeling them at different 

 depths, it will be easy to fudge of the temper of the bed ; 

 and it will also be proper to let a few of these sticks remain in 

 after the plants have been plunged, in order to ascertain the 

 warmth of the bed. When the tan is -good, one of these beds 

 l -retain a proper tlcgree of hc-,a ('/ nearly three months, 



and when the heat declines, if the tan be forked up and turned 

 over, and some new tan added to it, the heat will retvew 

 again, and will con-thiiie two months longer ; so that by turn- 

 ing over the contents of the pit, and adding some new tan 

 every time the heat declines, the bed may be continued for 

 a year: but it will still be proper, every autumn, to take oat 

 a large quantity of the old tan, and to add as much new in 

 its place, that the heat of the bed may be kept up in winter : 

 for the plants would 'suffer gi'eatly if it were suffered to de- 

 cline during the co'rd season. Before any tan is added in 

 winter, it should be laid in a dry place a week or ten days, 

 to dry; otherwise its moisture might chill the old ta j bed, 

 and prevent the fermentation : lience, unless the tan be turned 

 over again, there will be little or no heat in the beds, which 

 frequently proves fatal to the plants. Whoever therefore has 

 the management of these beds, should constantly and carefully 

 observe the warmth of the tati, because upon keeping the 

 beds in a proper temperature, their whole success depends. 

 Where this caution is not observed, it frequently happens 

 that the Ananas run into fruit very small, or with other plants 

 are infested by insects, both which are caused by the growth 

 of the plants being stopped 'by the decline of the heat of the 

 tan ; therefore great regard must be had to that, especially 

 in winter. The great advantages which these tan-beds have 

 over those composed of horse-dung, arc the moderate degree 

 of heat which they acquire ; for their heat is never so violent 

 as that of horse-dung, and they continue this heat ni-uch 

 longer; and when the heat declines, it may be renewed by 

 turning the beds over, and mixing some new tan with the old, 

 which cannot be so well done with horse-dung; and likewise' 

 the beds will not produce so great steams, which often injure 

 tender plants. Tan, we have already observed, is an excel- 

 lent manure for all cold stiff lands, after it can be of no 

 further service in the bat'k-bed. I'f it be laid upon grass 

 ground in autumn, that the rains in winter may Wash it into 

 the ground, it will greatly improve the grass; but when used 

 fresh, or in the spring of the year, just before dry weather, 

 it is liable to cause the grass to burn. Those who live near 

 plenty of Oaks, and probably at a great distance from any 

 tan-pits, will be pleased to learn, that Oak-leaves are well 

 preferable to the bark ; for they always 'heat regularly and 

 constantly, never heating with violence, or turning cold after 

 the furious heat is gone off: there is also a saving 'in expense, 

 for the decayed fermented leaves make good garden manure, 

 whereas rotten tan is wholly unfit for any horticultural pur- 

 pose. Having found plenty of the Oak-leaves, rake them 

 into heaps, carry them to some place near the hot-hoiist-, 

 fence them with hurdles, or whatever "will keep them from 

 being blown about, tread them well, and water them if they 

 be brought in dry. Ma'ke the heap six or seven feet thick, 

 and cover it with mats. In a few days the heap will come to 

 a strong heat, and 'in five or six weeks they will be properly 

 prepared for the hot-house. In getting them into the Pine- 

 pits, if they appear dry, water them again, and tread them 

 well, nill the pits are quite full. Then cover the whole with 

 tan two inches thick, and tread it till the surface becomes 

 smooth -and even. On this place the Pine pots, beginning 

 with the middle row first, and filling up the spaces between 

 the pots with tan, as when tan only is used. The leaves will 

 retain a constant and regular heat for twelve months, without 

 stirring or turning. After this, the Pines will have no occa- 

 sion to be moved, except when their pots are to be shifted, 

 &c. when a little fresh tan should be added. Without a cover- 

 ing of tan, the leaves, by their caking, will be liable to shrink 

 from the sides of the pots, and let the heat escape. 

 Tanner's Sumach. See Rhus Coriaria 



