618 TRANSACTIONS OF THE AMERICAN INSTITUTE. 



produces a highly porous churcoal, retaining the whole of the 

 iodine, by subjecting the seaweed to a low red heat in a closed 

 iron retort. The original sea-tangle thrown upon the shores of 

 these islands in the winter consists of large stems, each about 

 eiffht feet lonir and one and one-half inches in diameter. These, 

 when dried, slirink to about half an inch in diameter, and closely 

 resemble horn. After carbonization they expand to about three- 

 fourths of au inch in diameter, and contain about forty per cent, of 

 salts. When the charcoal is lixivated, fine colorless specimens of 

 salts are obtained, consisting of chloride of potassium, sulphate 

 of potash, iodine, bromine, and iodide and bromide of potassium. 

 The products of distillation saved are chloride of ammonium, 

 sulphate of ammonium, tar and pitch from the tar, oils, acetone , 

 naphtha and gas which is used for illuminating the works. The 

 charcoal, from its high porsity, is introduced as a deodorizer ; its 

 chemical composition resemliles that of animal charcoal, rather 

 than vegetable charcoal. This is especially interesiug, as tangle, 

 being a pure alga, is close to the border line, separating the ani- 

 mal from the vegetable kingdom. This charcoal can be aflbrdod 

 at about one-fourth the price of the animal charcoal. 



Ox THE SOUKCES OF FaT IN THE AxiMAL BODY. 



The authors last named presented a paper on this subject at the 

 last meeting of the British Association for the Advancement of 

 Science, in which they briefly viewed the opinions of eminent 

 scientists. In 1842 Baron Liebig had concluded that the fat of 

 herbivora must be derived, in great part, from the carbohydrates 

 of their food, but might also be produced from nitrogenous com- 

 pounds. Dumas and Boussingault at first opposed this view, but 

 subsequently the experiments of Dumas and Milne Edwards with 

 bees, of Persoz with geese, of Boussingault with pigs and ducks, 

 and of the authors with pigs, had been held to be quite conlirma- 

 tory of Leibig's view, at any rate as far as carbohydrates were 

 concerned. But at the meeting of the British Association in 1864, 

 Dr. Haydcn expressed doubt on the point; and at the Congress of 

 Agricultural Chemists held in Munich last year, Professor Voit, 

 from the results of experiments with dogs fed on flesh, maintained 

 that fat must have been produced from the nitrogenous constitu- 

 ents of the food, and that these were probably the chief if not the 

 only source of fat even in herbivora. Baron Leibig disputed this 

 conclusion, and his sou^ Hermann v. Liebig, had since sought to 



