TRANSACTIONS OF THE SECTIONS. 57 
solutions of cobalt either by hydriodic acid or iodide of potassium, or by iodice acid 
or iodate of potassa,” The author finds, however, that cobalt yields to the action of 
the ammonio-iodide solutions after some hours’ digestion and a little heat and water. 
As might be expected, it exhibits very strongly the sympathetic properties of the 
chloride; for when placed on paper and gently heated, it becomes a brilliant green, 
which of course vanishes as the paper cools, 
The prismatic crystals obtained by evaporation on a slip of glass and mounted in 
balsam are decidedly acted on by polarized light ; but the chief value of this new com- 
pound will be found in its properties as a photographic agent. 
When used for the purpose of iodizing collodion, it certainly produces richness of 
detail in those parts of the picture where iodide of potassium often fails, and it is also 
exceedingly sensitive to the action of light when ordinary attempts would be fruitless. 
Photographic chemists may therefore profitably turn their attention to this compound. 
Ammonio-iodide of Titanium.—As titanium, which resists every direct method of 
attack in the laboratory, yields after a period of digestion in the iodine solution, it is 
probable that other of the scarcer metals, which are with difficulty reduced by the 
ordinary methods, might be exhibited in the form of ammonioc-iodides, and thus throw 
additional light on their respective equivalents. 
The crystals of ammonio-iodide of titanium which Mr. Reade obtained, were from 
a pure specimen of the metal obtained by Mr. Waterhouse, of Halifax, from the slag 
of the neighbouring iron furnaces at Low Moor. 
Ammonio-iodide of Aluminium.—In forming this compound, Mr. Reade used not 
the pure metal, but alumina only, precipitated in the usual way. After allowing the 
alumina to digest for some time in the iodine solution, the whole was boiled in a little 
water, which dissolved the new compound, and upon evaporation and the proper mea- 
sure of heat to volatilize the excess of iodine and ammonia, a white semi-metallic 
substance remained, as in the case of silver, It is soluble in dilute hydrochloric acid, 
and yields a blue precipitate on the addition of yellow prussiate of potash, Whether 
any use can be made of this process towards obtaining the pure metal, is a problem 
for practical men. f 
On Fused Wrought Iron. 
By E. Rirey, P.C.S (Communicated by Dr. Ovi1Ne.) 
The author had succeeded in running down, with great facility, several ounces of 
best cable bolt-iron into buttons of metal, which presented on fracture a beautiful 
lamellar structure, and worked extremely well at a low heat; but which, after having 
been exposed to a welding heat, was altogether useless, from its property of cracking 
or crumbling. See eee 
On the Nutritive Properties of the Potato, when properly manipulated, as 
compared with Wheat, $c. By Jasver W. Rocerrs, CLE. 
The object of the writer was to introduce the use of the potato for the manufacture 
of flour and meal analogous to flour and meal of wheat and oats, and thus to preserve 
the potato in a state equally fit for the food of man. It was an error to imagine the 
potato had not the same elements of nutrition as wheat and oats. The nutritive pro- 
perties of the potato, when deprived of its average quantum of water, which might 
be stated at 75 per cent., were as follow:— 
, OF Starch.) st av eue © @ es was , OF 0L0 per cent, 
MECCIMEEN ste, sora) Gall a) ar ett et, etal Reto rf 
yy Ol Eig UR Seer Pale aay onl 4: rr 
Whilst the nutritive properties of wheat are— 
Ofratarchy (fo oo ah ho) alate ee ett30)782109 per cent. 
” gluten pe UB el an he ee ew! pe ee 17-536 ” 
‘ RANGILO price fo ape ssany ppt te elton wilt tog h4e95gts 9:4) 
‘ Why then should the potato be used merely boiled or baked as a garden vegetable, 
_ whilst by proper manipulation it might be converted into a material for producing 
meal and flour nearly, if not fully, equal to wheat, and of a nature also, that resists 
the usual action of climate and decay, as had been abundantly proved by its trans- 
mission to the tropics, as well as by tests made by the writer under the orders of 
Goyernment in producing several descriptions of food from potatoes at the South 
Dublin Union ? ; 5 
