298 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 
showing a gain of £11. 7s. 3d. per acre in favour of 1 cwt. of muriate of 
potash. This we think is probably due to the dressing of muriate of 
potash being too large ; as the potash is in the form of potassium 
chloride, and when used in excess chlorides are most injurious to plant 
life, unless applied a considerable time before planting ; now in this case 
they were applied in the drill immediately before planting. The appli- 
cation of 2 cwt. of muriate of potash increased the size of the saleable 
tubers, but reduced the percentage by 2'75 per cent. 
In testing the effects of different manures on the cooking quality 
of the potato, it was found that those grown with sulphate of ammonia 
were white, dry and mealy, and of good quality, whereas those raised 
with nitrate of soda, were waxy, wet, dark in colour and poor in quality. 
The test in each case was carried out with the same variety of potato. 
The effects of potassic manures were also tried, and those raised with 
kainit were wet, pasty, and dark in colour, but bjth sulphate and 
muriate of potash produced dry, floury potatos, quite white in colour. 
The quality of potatos depends upon other conditions besides 
manures, the most important being the variety. Some potatos are natu- 
rally white in colour, while others are dark, yellow or red streaked ; some 
are poor in starch and rich in water, while other varieties are very rich 
in starch. The soil upon which they were grown has also a great influence 
upon the quality. Peaty or wet stiff clays invariably produce wet, waxy 
potatos ; but sandy loams, sandy and alluvial soils generally produce those 
of first-class quality. 
Dry seasons are usually conducive to the production of floury potatos, 
and wet seasons have the opposite effect ; finally, the quality depends 
largely on how they are cooked. This question of quality is really one 
of the most important, because bad cooking varieties are almost unsale- 
able ; we require therefore to be very careful in the selection of our 
varieties. 
In order to be successful in growing potatos, it is wise to select good 
sound seed of heavy-cropping varieties, of good cooking quality, white 
in flesh, with shallow eyes which ensure least waste in peeling. The 
land must be well cultivated before and after the potatos are planted, in 
order to have as fine a tilth as possible, and moderate dressings 
of farmyard manure should be applied, supplemented with a complete 
mixture of artificial manures containing nitrogen, phosphorus, and 
potash in suitable quantities for different soils. 
