222 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 
cious and cheapest methods of subduing the growth. It is almost impossible 
permanently to eradicate the fern. Where spraying seems the most convenient 
cure, salt is the best material to use, 150 pounds of salt dissolved in 60 gallons 
or more of water to the acre for each application is sufficient. — M. L, H. 
Fertilizer Problem from the Vegetable Grower's Standpoint. By C. E. 
Durst (U.S.A. Exp. Stn., Illinois, Circ. 182, May 1915 ; figs.). — Though the 
general principles of soil fertilization are of course always the same, there are 
marked differences in their application to vegetable and to farm crop production. 
In crop-growing, quantity and proper maturity are the only objects to be aimed 
at. The vegetable-grower has many more points to take into consideration. 
Relatively small differences in earliness, flavour, quality, or size may make all 
the difference in the value of his crop, and the margin of profit is so much larger 
as a rule that there is scope for more costly methods of cultivation. The whole 
question is reviewed. — M. H. L. 
Fertilizers, The Nitrogen of Processed. By E. C. Lathrop (U.S.A. Dep. 
Agr., Bull. 158, November 1914). — Waste organic compounds or base goods, 
such as hair, garbage, tankage, leather scraps, etc., are mixed with rock phos- 
phate, and treated in a den with sulphuric acid. 
The mass is allowed to stand for several days, until cool enough to handle. 
A hydrolysis of the proteins takes place, and the crude non-available types 
of nitrogen present are changed into much more available forms, and field experi- 
ments show that such fertilizers give equal and in some cases better results than 
dried blood and the other high-grade materials. 
The above method is strongly recommended as a method of treating low-grade 
waste products to increase the sources of plant nutrition. The higher grades 
of organic compounds are becoming too scarce and expensive to be economical 
as plant foods, this being due largely to their use as animal and poultry foods. 
C. P. C. 
Flea Beetles. By C. L. Walton, M.Sc. (Ann. Appl. Biol. iv. Nos. 1 and 2, 
Sept. I, 191 7 ; pp. 6-7). — These pests appear to wait the advent of suitable 
crops and dry, sunny weather, when they multiply rapidly. Heavy rain limits 
or ends their ravages. Young root crops on dry slopes and hill-sides are generally 
most damaged, and delay in growth, with conditions of weather favouring the 
beetle, may cause total failure of first sowings and damage to the second. 
Comparatively few complaints were received from lands regularly dressed 
with lime and basic slag. Soaking seed in paraffin proved of benefit. A common 
weed, Polygonum Persicaria, was badly riddled by the beetles. — R. C. 5. R. 
Forest Pathology in Forest Regulation. By E. P. Meinecke (U.S.A. Dep. Agr., 
Bull. 275, April 7, 1916). — It is clear that in the most important branch of forestry, 
silviculture, the blind adoption of European methods must cause serious 
difficulties. Even in Germany, many of the fundamental problems of forest 
organization are steadily discussed, and are far from being considered settled. 
European foresters have not yet developed a true system or science of silvi- 
culture capable of being applied to virgin conditions or to all conditions. 
A, D. W. 
Fruit Drying. By W. J. Allen (Agr. Gaz. N.S.W. vol. xxviii. pp. 13-29, 
95-106; 21 figs.). — To dry peaches, apricots, and nectarines whole, dip the 
fruit in boiling caustic soda solution (1 lb. to 8 gallons of water) for one or 
two seconds, spread on trays, transfer to the fumigator, where it is exposed to 
the fumes of burning sulphur for eight to twelve hours. Dry by sun or artificial 
heat, and then place in calico bags to protect from moths. If the fruit is cured 
in halves the immersion in caustic soda is omitted. Suitable peaches for drying 
are ' Elberta,' ' Early and Late Crawford,' ' Salwey ' and ' Lady Palmerston.' 
' Moorpark ' is a good Apricot. 
The best prunes are ' Prune d'Agen ' and ' Robe de Sergent.' They are 
dipped in boiling soda solution (1 lb. to 12-20 gallons) until the skin begins 
to crack. This usually takes from three to ten seconds. After fumigation and 
drying, the prunes are placed in sweating boxes for three or four weeks, and 
turned over once a week. Finally, the fruit is dipped in boiling water con- 
taining a little salt and some broken prunes for five minutes. It is again dried. 
Apples are peeled, cored, sliced by machinery and dropped into weak brine 
(2 oz. salt to a gallon). The slices are quickly placed on trays and exposed to 
fumigation until they acquire a nice colour (usually 15 minutes). Dry for six 
