NEW ENGLAND FARMER. 



301 



the rot. We have occasionally given our views on 

 the main cause of this disease. We consider it at- 

 mospheric, and yet there are other predisposing or 

 secondary causes, such as wet, heat, soil, manure, 

 sudden alternations from heat to cold, and the reverse, 

 &c. The tenderness of some varieties is another 

 predisposing cause. 



We can tell whether potatoes are rotting, gen- 

 erally, without inquiry or examination, from the pe- 

 culiar state of the atmosphere. Yet this is not the 

 main cause, for the state of the Aveather which favors 

 the rot has occurred occasionally almost every year 

 since our remembrance, and the severest cases used 

 to cause rust only, with one exception. 



Early in August, year before last, we observed that 

 potatoes would rot extensively, and we were laughed 

 at for the remark, for they never looked more lux- 

 uriant than at that time ; but the truth of our asser- 

 tion was soon evident. 



We have no doubt that insects, and various dis- 

 eases in the potato, may act with the rot, or operate 

 on the potato at the same time ; and hence they may 

 be regarded as a cause. Sometimes the course of the 

 rot seems to be along almost on a line, and it comes 

 suddenly, like the passage of a breeze, a current of 

 fog, or a volume of smoke, very unlike the operations 

 of insects, both in its passage, places of operation, 

 and suddenness of action. Last year it was evident, 

 even to the last of September, that there had been 

 but very little rot ; and some thought that it was dis- 

 ajipearing, and that we soon should have the pleas- 

 ure of seeing it no more forever. But we took no 

 such view of the case, for the weather, last season, 

 was remarlcable for being unfavorable to the rot. 



This season, at one period we had rain nineteen 

 days out of twentj'-two successive days, and part of 

 the time the weather was exceedingly warm, and 

 there were occasionally interspersed cool nights. 

 After this, it was not necessary to examine the pota- 

 toes in order to see w'hcther they were rotting. 



There is a simple and convenient remedy or pre- 

 vention of the rot, which is, to cultivate hardy kinds 

 of potatoes ; but farmers will not follow this safe rule 

 on account of the popularity of Chenangoes, and 

 some other kinds in the market. They will run the 

 risk of losing half of their crop, for the sake of hav- 

 ing a ready sale for the other half. Although it is 

 well known that the Chenango is very liable to rot, 

 and almost every farmer has lost them to a great 

 extent, yet it is the principal kind cultivated. — En. 



For the New England Farmer. 



VALUABLE PROPERTIES OF TAN. 



Mk. Ei)rroK : I propose to write an article on what 

 is visually called tun, and I shall speak of its valuable 

 properties when used for horticultural purposes. 

 And first, let me say, what I shall write upon the 

 subject will relate wlioUy to the spent bark of the 

 hendock spruce, and not to any species of the oak. 

 A great deal is said, at the present time, in our hor- 

 ticultural journals, in regard to the i)roj)orties of tan, 

 without informing us to which of the kinds they 

 refer. 



It should be known, that tan from the bark of the 

 oak possesses entirely different properties from that 

 obtained from the hemlock. The former, when suf- 

 fered to remain in a heap, quickly engenders heat, 

 and is comparatively easily decomposed ; while, on 

 the contrarj', the latter is very slow in decomposi- 

 tion, and will usually engender but a very little, 

 if any heat, and is generally known to possess the 

 property of preserving ice, when placed around it. 

 The gallic acid, or tanning principle, is not so great 

 in the bark of the oak, and is given out more readily 

 and entirely than it is from the bark of the hemlock ; 

 for in the latter kind of bark, in consequence of the 

 resin it contains in its ross or epidermis, it retains a 

 portion of its astringency after it has been for a long 

 time steeped in a vat, more especially that poition 

 laying immediately over the liber. 



It is probably for this reason that fresh hemlock 

 tan applied to a tree or plant, by placing it near its 

 roots, injures it, and stops its growth ; and it is from 

 the same cause that the growth of grass around 

 trees is prevented. We have seen a hyacinth, 

 grown upon water in a glass, soon checked in its 

 growth by placing a small piece of hemlock bark in 

 the water — the plant feeling the bad effects of its 

 astringency by the contraction of its roots. Hence 

 it is obvious that tan fresh from the vat should not 

 be placed near the roots of trees or plants. Now, 

 this astringency, gallic acid, or tanning principle, is 

 nearly lost or destroyed in a few months, and it can 

 then be safely used for horticultural purposes ; but, as 

 a general rule, the more decomposed or rotten it is, 

 the better. It decomposes more rapidly when mixed 

 with earth or other substances, more particularly 

 lime. Its properties, when rotten, are the same, I 

 should think, as decayed wood or chips ; and in this 

 state, when placed around fruit-trees, it is very ser- 

 viceable, by rendering the earth more light and moist, 

 in which the roots delight to grow and creep. 



We have found gardens with a heavy soil, much 

 improved by ploughing in old tan, thereby rendering 

 it more light. Tan forms a good material for walks 

 and paths in a garden, they being easily made and 

 kept in repair, pleasant to tread upon ; and it has 

 this advantage over gravel — should it ever become 

 necessary to make an alteration in them, it could 

 without injury be ploughed into the soil of the gar- 

 den. We have found it particularly serviceable when 

 placed around strawberry plants in autumn, as it 

 protects the roots from the frosts of winter, and in 

 summer answers the purpose of mulching, by keep- 

 ing the ground moist and the fruit clean, and in its 

 decay forms a light mould, in which its roots love to 

 penetrate and fasten. 



We need no better proof of the fondness of plants 

 or trees for old hendock tan in a state of decay, than 

 from the fact that if when shooting forth their roots, 

 they enter a tan walk or path, they will traverse it 

 lengthwise, creeping in it a great distance, without 

 leaving it for the rich soil around it. 



A very great amount of good matter, suitable for 

 horticultural j)urposes, could be collected every year 

 in Danvers and Salem, from their numerous tanneries ; 

 consisting of substances always accumulating in tan- 

 yards, such as liair, lime, the emptyings of drenches, 

 and water pits, the fleshings of hides, S:c. ; these 

 collected and mixed together with a large portion of 

 tan, would form a valuable compost. It is by these, 

 scrapings of a tan-yard, that we have been able to 

 bring a large garden to a high degree of cultivation 

 in a few years. We can therefore with confidence 

 recommend tan, when suitably prepared and applied 

 to lieavy soils, for horticultural purposes. We have 

 had no experience in applyiug hemlock tan to light 

 soils. Yours, 



S. P. FOWLER 



Danvehs New Mills, Aug. 21, 1850. 



