THE MANUFACTURE OF KELP. 299 



possible that the utilitarian spirit of this age will permit this enormous 

 waste to continue 1 Unless the lairds of the kelp districts take the subject 

 up themselves it will still be so, for they cannot expect their poor tenants 

 to erect works for tbis purpose, as the lion's share of the advantage must 

 ultimately fall to their own lot. With the view of interesting them in the' 

 subject, I beg to call attention to the following proposed improvements : — 



1. Seaweeds of all kinds are to be stored in sheds ; they keep perfectly 

 well under cover ; they should be first collected in heaps, to drain off the 

 superficial water, and then laid out in drying sheds ; in summer, advan- 

 tage may be taken of the sun's rays. Seaweeds when laid out thin, are not 

 so difficult to dry as is generally supposed, and when dry keep perfectly 

 well under cover. 



2. The seaweeds thus dried are then to be compressed into cakes, by 

 hydraulic or other pressure ; this is not essential, but the cakes occupy less 

 room in stowage, and if the charcoal obtained is to be used for fuel, this 

 treatment improves it. 



3. The cakes, or the impressed weed, are then to be distilled at a low 

 red heat, in iron retorts ; the tar and aqueous products to be collected in 

 suitable condensers, and the gas in a gasometer. The gas maybe employed 

 for heating the stills used for rectifying the products, for heating the 

 drying sheds, or even for lighting the factory ; it might even be treated 

 according to Pettenkofer's method of superheating, and used as a means of 

 lighting a district. The best kind of retort for the purpose will, I think, 

 be cylindrical vessels of wrought iron, heated externally, and placed verti- 

 cally, having the base and also the upper end conical ; the former furnished 

 with an air-tight iron damper plate, for withdrawing the charge when the 

 carbonization is complete, and the latter provided with a moveable iron 

 hopper for introducing the charge. 



4. The charcoal is to be lixiviated and treated as ordinary kelp, and 

 then thrown out in heaps to dry in the air. When raked from the retorts 

 it should be allowed to fall into the lixiviating water, or into iron boxes, to 

 protect it from the air ; if the latter plan be adopted their heat may be 

 rendered available for drying the weeds by wheeling them into the drying 

 shed. The lixiviation will require larger tanks for its conduction than 

 those at present employed, on account of the greater bulk of the charcoal ; 

 it has the advantage, however, of floating on water, and as the water in 

 contact with it, when saturated, sinks to the bottom, it is quickly replaced 

 by a fresh portion, and the solution is thus rapidly effected. The solution 

 would be roughly evaporated to dryness, and the salt thus obtained sold to 

 the lixiviator. 



5. The washed and air-dried charcoal is to be used for heating the 

 retorts and evaporating the solution of the salts. Should, however, peat be 

 very abundant in the neighbourhood this charcoal may be manufactured 

 into manure, by treating it with the ammoniacal liquid ; or be applied to 

 some of the many uses for charcoal, and the peat employed as the fuel. 

 The ash from the charcoal is a valuable manure ; it usually contains over 



