i9i i.] Summary of Agricultural Experiments. 509 



as sets, 53 produced plants which showed no signs of infection with 

 the blight until about thirteen weeks after planting, when the disease 

 was found as isolated spots on the leaflets indicating an attack by 

 spores from a neighbouring diseased plot. It does not seem possible 

 that the blight could have arisen from internal mycelium, as the parts 

 of the plants other than the leaflets were quite healthy. The new tubers, 

 moreover, were in every case found to be quite healthy. 



It is concluded that there is no evidence to support the view that 

 the recurrence of the potato disease, year after year, is due to the 

 migration of dormant Phytophthora mycelium in or into apparently 

 healthy plants. 



Horticulture, Cider, and Hops. 



Processes of Cider-making (Nat. Fruit and Cider Inst. Rept., 1910). — 

 Washing of Vintage Fruit. — The cider-making season of 1909-10 

 was considered a suitable occasion, owing to the unfavourable character 

 of the season and the unsatisfactory condition of the fruit available, for 

 testing the effect of washing the fruit before milling. Almost the whole 

 of the fruit used was washed — first in a large tub, and then in a 

 sloping wooden trough, the bottom of which consisted of laths f in. 

 apart. The amount of dirt, decaying leaves, &c, removed from the 

 fruit was remarkable, but, on the whole, no very striking results as 

 regards the cider were produced in the case of fruit in reasonably good 

 condition. With two ciders made from fruit in good condition, one-half 

 of which was washed and the other unwashed, a difference in the 

 flavour could only be detected as the season advanced, when the flavour 

 of that from the washed fruit became slightly cleaner. There was an 

 absence of taint in the ciders and less "sickness" than usual, but this 

 may not have been due to the washing. Washing was, however, un- 

 doubtedly of service where the fruit was in a bad state, and the practice 

 might profitably be adopted as a preventive of taint by those who have 

 large quantities to deal with, and accordingly are not able to ensure 

 such good general condition as those who handle smaller quantities. 



Maceration of the Pomace. — Further experiments have been made to 

 ascertain the reason of the value of allowing the pomace to stand 

 some time after milling before it is pressed, and former results have 

 been confirmed, viz., that there is no material increase in the amount 

 of sugar in the juice. Accordingly, the explanation has been sought 

 in other directions. No striking changes are produced in the amounts 

 of acid and tannin in the juice, and the natural rate of fermentation is 

 also not much directly affected. A consequence, however, of allowing 

 the pomace to stand, or maceration — as it may be called — is that a larger 

 quantity of mucilaginous or pectic substances becomes dissolved in the 

 juice. Some of these substances are later deposited in flocculent, or clot- 

 like forms, and act as a natural clarifying agent, and it is suggested 

 that the advantage of maceration is due to the heavier and more floccu- 

 lent deposit in the juice from macerated pomace and the more thorough 

 and quicker clearing. If this is so, the value of the process may be 

 less since the introduction of the filter. It was found, however, that 

 ciders made from macerated pomace could be filtered at an earlier 

 stage of fermentation and more thoroughly than others, and this may 

 be of considerable value in dealing with rapidly fermenting ciders, 



