306 



MONTHLY JOURNAL OF AGRICULTURE. 



Tlie breaking up of the tubers into a pulp is 

 accomplished by means of cutting cylinders, to 

 which the potatoes are supplied from a hopper, 

 nearly as grain is to a mill. The more rapidly 

 the cutters move, the finer is the pulp produced, 

 and the more perfect the subsequent extraction 

 of the starch, and hence they generally make 

 600 to 900 turns in the minute, and as these cyl- 

 inders are usually about twenty inches in dia- 

 meter, their periphery moves with a velocity of 

 fi-om 1000 to 1500 yards in a minute. A single 

 cylinder of the above dimensions, and of sixteen 

 inches long, making 800 revolutions in a minute, 

 will reduce to pulp about fifty bushels of pota- 

 toes per hour. This for the twelve working 

 hours is about ten tons. 



The object of pressing or sifting the pulp is to 

 separate the fecula from all foreign substances, 

 especially from the cellular tissue, which, being 

 coai'ser, rests on the seive through which the 

 fine starch passes. A gi-eat variety of mechani- 

 cal arrangements have been constructed for this 

 purpose, which fulfil their object, but there re- 

 mains always with the residual pulp 2 or 3 per 

 cent, of the fecula, which it is impossible to ob- 

 tain. 



The starch, diffused in the current of water by 

 which it has been washed out from the pulp, is 

 run into vats, where it is poured oft', and fresh 

 water put on : finally the starch is taken out and 

 dried on floors. As it consolidates into very firm 

 masses, it requires finally to be broken down by 

 a kind of bolting machine, before being put up 

 for sale. 



It is necessary to add some valuation of the 

 money circumstances of this manufacture. An 

 acre of potatoes, very well manured, and on 

 good land, may be considered to produce nine 

 tons of potatoes, which may be taken as worth 

 i;i5. From such potatoes it may be expected, 

 that, with proper care, 15 per cent, of pure 

 starch may be extracted, and hence, from the 9 

 tons, 27 cwt. The market price of the potato 

 starch is variable ; it has been 30s. per cwt., but 

 it only on rare occasions falls below 20s. Ta- 

 king it at 2()s. the value of the produce of the 

 acre becomes £27, leaving for cost of manufac- 

 ture and profit £12, and of this certainly a large 

 proportion should be profit. I do not think I 

 value the potatoes too low, as, of course, the 

 manufacturer, if not himself the grower, would 

 purchase for store at proper seasons, and avail 

 himself of the lowest terms. 



But this calculation of advantage supposes the 

 starch to be the only valuable matter extracted 

 from the potato, which is far from being the 

 case. The residual pulp, which, when perfectly 

 dry, amounts to about 5 per cent, of the entire 

 weight of the tubers, has been found a most 

 nourishing food ; in fact, it contains most of the 

 nutritious part of the root, the mere starch which 

 was removed being comparatively much less 

 important in nutrition. This pulp, if moist, pu- 

 trefies rapidly, it is rich in nitrogen, and in fact 

 analogous to animal substances in compo.sition. 

 and, consequently, if not required for food would 

 form, by being made with hme and clay into a 

 compost, a manure of gi-eat value, and especially 

 suitable for restoring to the potato ground the 

 substances which the crop in s^ow-ng had re- 

 moved. The waters with which the pulp is 

 first washed, dissolve a quantity of the soluble 

 constituents of the potato. They rapidly putre- 

 fy, and exhale an odor so rotten as to have ren- 

 dere/i the starch factories near Paris a nuisance 

 to the neighborhood, until it was suggested to 

 (606) 



employ this water as a manure, which has been 

 perfectly successful, and at once removed an im- 

 portant dra'wback to this branch of industry, and 

 materially increased the fertility of the surround- 

 ing farms. 



If these residues be properly economized, it 

 is evident that the cost of growing the potatoes 

 may be materially diminished. The atmosphere, 

 in itself, furni.shes in fact the carbonic acid and 

 water from which the starch is fonned, and if 

 the matters taken fi-om the soil in each crop, be 

 returned to it in the residues of the maimfacture, 

 the cost of manure, so heavy for this pai'ticular 

 plant, may be almost entirely obviated. 



In this country, where the extensive use and 

 culture of the potato have become almost a na- 

 tional characteristic ; where labor not requiring 

 considerable skill is to be had so cheap ; where 

 potatoes are at their minimum price ; it is not 

 merely to be regretted but absolutely disgrace- 

 ful to ourselves, that we import from Scotland 

 and from France, large quantities of the potato 

 starch to be consumed in Ireland. 



The starch is not the only material extracted 

 from potatoes, and extensivelj' available in the 

 arts. The potato itself, reduced to flour, is at 

 present extensively employed upon the Conti- 

 nent in the preparation of a very wholesome 

 quality of bread, and the starch itself is consu- 

 med in making confectionary, jellies, sago, tapi- 

 oca, in thickening paper, and in a variety of 

 uses, by which such quantities of it are employ- 

 ed as to render its manufacture a really impor- 

 tant and e::«ensive department of industry. The 

 most remarkable of all the applications of potato 

 starch is, however, one to which the excise laws 

 of this country would probably present invinci- 

 ble impediments. It is the preparation of sugar 

 and of spirits. Under the influence of certain 

 chemical agents, simple, yet peculiar in their 

 action, and to which it would be my province 

 here to refer in detail, starch is converted into 

 sugar, and this sugar, by fermentation, yields 

 spirits. On the Continent the manufacture of 

 spirit from corn is almost abandoned. Potato 

 spirit is almost universally used; and in flavor 

 it so resembles brandy, that it is well known 

 that a large quantity of the French brandy 

 brought into London, is potato spirit from Ham- 

 burgh, colored with burned sugar." 



15^ Mr. Bland, of Ripon, has an apple tree 

 in his garden which has blossomed thrice this 

 year. There are now^ upon it two crops of ap- 

 ples, and the blossoms for a third have just set. 

 [English Paper. 



J^^ The London Times estimates the cap- 

 ital of seventy-four railwavs completed, or in 

 course of completion, at £103,166,220— of pro- 

 jected branches of these, at £35,000,000. and of 

 707 new companies, either estabhshed or pro- 

 jected up to date, at £464,698,656— making a 

 total of £602,864,876 ! 



t^' The system of smuggling by means of 

 dogs is represented by the Valenciennes jour- 

 nals to be still carried on with unabated activi- 

 ty. A few days ago ten dogs, laden with tobac- 

 co, and two men who had the direction of them, 

 were caught by the officers of the customs at 

 Alescon. [English Paper. 



