294 THE MANUFACTURE OP KELP. 



The residuum in the still, after the distillation of the ammonia and 

 naphtha, was found to be a solution of acetate of lime ; distilled with hy- 

 drochloric acid, this furnished acetic acid, the last portions of which con- 

 tained also butyric acid. 



The tar was distilled with water, a volatile oil of very peculiar odour 

 was thus obtained ; the odour recalls that of burning seaweed. In the crude 

 state it contains about 1*2 per cent, of the naphtha, and about 1*6 per cent, 

 of a body analogous to kreosote. Diluted hydrochloric acid removes from 

 it about 3*7 per cent, of a mixture of volatile alkaloids containing picoline, 

 &c, and a red pitchy colouring matter is separated. It also contains pyrroL 

 After purification with oil of vitriol and caustic soda, the oil presents the 

 appearance and properties of a mixture of pure hydrocarbons analogous to 

 those from coal-tar naphtha. Its sp. gr. is 841, and its boiling point rises 

 from about 180° to above 400° Fahr. This oil must not be confounded 

 with that obtained by Dr. Stenhouse, in distilling some species of Fucus 

 with sulphuric acid, and named by him fucusol, and from which he pre- 

 pared fucusamide and fucusine. The oil here treated of is a pure hydrocar- 

 bon, and has not been hitherto obtained from this source. It will be 

 applicable to many of the uses for which coal-tar naphtha is so much in 

 demand. The colouring matter separated by an acid from the oil is a 

 product of decomposition. It is soluble in oil of vitriol, gacial acetic acid, 

 alcohol, and methylic spirit. It is insoluble in water, either cold or boil- 

 ing, and separated from all its solutions by its addition ; it is also insoluble 

 in chloroform, ether, benzole, bisulphide of carbon, oil of turpentine, the 

 fixed oils, and dilute acids. It is unaffected by boiling hydrochloric acid. 

 Nitric acid has no effect on it in the cold, but decomposes it when boiling, 

 forming oxalic acid. Boiling oil of vitriol carbonises it. It is decolorised 

 by chlorine. The caustic alkalies partially decolorise, but do not dissolve 

 It ; the colour is restored by an acid. It is, however, chiefly remarkable 

 in containing iodine, and it holds it in such close combination that boiling 

 solution of potash does not remove it, and it is only when fused with 

 hydrate of potash that it can be detected. It is thus converted into oxalate 

 of potash and iodide of potassium, it was found to contain 35 per cent, of 

 iodine. I do not anticipate that it will be valuable as a dye, as it shows a 

 tendency to fade ; in a chemical point of view I look forward with interest 

 to its thorough examination when I shall have obtained it in sufficient 

 quantity ; the greater the heat employed in distilling the weed, the more of 

 this substance is produced. The tar, after the volatile oil had been removed, 

 presented the appearance of Stockholm tar, which it might well replace ; it 

 was then distilled alone, and a fixed oil thus separated ; this contains on an 

 average 5-2 per cent, of a crude acid, analogous to kreosote. The oil, after 

 this has been removed by potash, is purified with oil of vitriol, and it then 

 resembles the paraffin oil of commerce. It will thus be seen that all these 

 products are of considerable commercial value, and it remains now to show 

 what are the quantities yielded — the same species were experimented on for 

 this purpose — the weeds were compressed into cakes, and distilled in a 

 small iron gas retort — 'the quantitative results are shown in the following 

 tables. 



