ON IMMERSING POTATOES IN AMMONIACAL WATER. 265 
immersed for four or five days in ammoniated water, containing an 
ounce of the common liquor ammonise to a pint of water, they will on 
removal he found to have their vegetative principle destroyed or greatly 
checked, so that they may be preserved throughout the year without 
deteriorating their general qualities. The temporary action of the 
ammonia in no way affects the potato beyond destroying its power of 
growth ; if however any change is produced, it is rather beneficial than 
otherwise, somewhat improving the appearance and flavour of inferior 
potatoes, and giving them a mealiness they did not possess; not a trace 
remains behind, nor could the most fastidious ever detect that the 
potatoes had been immersed in ammonia. 
The exportation of potatoes to foreign climates, chiefly within the 
tropics, is an object of importance, particularly for the comfort of sailors ; 
nothing in the way of diet is a greater luxury than a potato with their 
salt food. The expense of immersion is very trifling, and the potatoes 
subsequently require to be spread in an airy situation to dry. There 
is another effect produced by the continued immersion of the potatoes 
in the ammoniacal water, viz. a consolidation of the starch and fibre, 
and the loss of the water of the potato. If instead of removal in five 
days, the potatoes be continued three weeks in the ammoniacal water, 
they become tough and shrivelled, and on being removed and dried by 
exposure to the air, assume a new form; the potato appears consoli¬ 
dated and the qualities are greatly lost, for on boiling it assumes the 
appearance of sago or starch, yet still firm and retaining its form. But 
if used in its dry and uncooked state it has a mealy flavour and the 
properties of corn. No chemical change is effected, but merely a 
mechanical consolidation and extraction of moisture, for precisely the 
same effect is produced by immersing potatoes in strong solution of salt 
and water, taking great care to remove by washing the whole of the 
salt, and this requires some time and repeated changes of water. This 
mode is cheap, within the reach of every one, and may perhaps be found 
applicable to the conversion of refuse potatoes into food for cattle or 
pigs, being sweet, good, and wholesome, and very nutritious dry diet. 
The hydrate of potato starch forms a very tolerable tapioca for pud¬ 
dings ; potato starch mixed with a little lime and boiled produces a 
very hard, tough, semi-transparent mass, tasteless, insoluble, and pos¬ 
sessing the properties of a strong paste and useful cement. (Abridged 
and compressed from a paper in Part 1, Vol. I., of the Transactions of 
the Society for Encouragement of Arts, &c., by Mr. W. H. B. Web¬ 
ster, of Ipswich, for which the thanks of the society were voted to him.) 
The same book contains an account of the Mexican mode of drying 
plantains, with suggestions for making this an article of colonial com- 
VOL. IV.-NO. XLIX. 
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