252 On the Chemical Examination of 



F. digitatus, F. vesiculosus, F. nodosus, and F. serratus, in 

 Liebig's Annalen, vol. liv., p. 350, by Mr J. Gbdechens of 

 Hamburg, published in 1845. The following table gives the 

 calculated mean of these analyses : — 



Potash, 11*67 



Soda 12-54 



Lime, 11-32 



Magnesia, 8*29 



Oxide of iron, . . . l oea \ . Pg&iwtfd 



Chloride of sodium, .... 20-61 



Iodide of sodium, .... 1-33 



Sulphuric acid, « «■ r 7 ? ' :8 ^* ? VI ^9-77 

 Phosphoric acid, . IT 9&Bfl 8£W 2-19 



Silica, . . eaik its gao&te Ajftlw f INMf ^19V 

 Carbonic acid, . . « IJ30 -8fl >ii'ioq d/$' 2 7 



Carbon, . . < 9 jtfjrfaa"-^ha(Q ajsvr rt .fi'^ gorri 

 c doidw t i9bwoq . ,7 <i9i/iY/ ni bsylosa^mjofeefli 



i'fsq 9mj599d .boiiirgi aad 

 Analysis of Orkney Drift-Weed Kelp. 



For the specimen of kelp subjected to examination I am 

 indebted to W. Paterson, Esq., alkali-merchant, Glasgow. 

 The investigation was conducted in the laboratory of the Uni- 

 versity of Glasgow, under the superintendence of Dr R. D. 

 Thomson. In making these analyses the first points to be 

 determined were, the quantity of soluble and insoluble salts 

 and water. To effect the first object, a portion of the kelp 

 was digested in water, the solution and residue thrown upon 

 a weighed filter and washed till all the soluble salts were 

 removed. The insoluble salts were then dried at 212° F : — 



t . ,, An Soluble Salts Insoluble Salts Solu ^le Salts 

 Insoluble Salts. , w , , and Water 



and Water. per cent. 



1 per cent. 



400 grains gave 11480 285*20 28-700 71*3 



500 ... 155-49 344-51 31-098 68902 



1000 ... 294-10 705-90 29-410 70-59 



Mean, 29-736 70-264 



Water. — The quantity of water was estimated by heating 

 the kelp at 212° F. till it ceased to loose weight : — 



Water. AVater per cent. 



200 grains gave 13-60 6*8 



If the quantity of water be subtracted from the soluble 



