December, 1909.] 



521 



Timbers, 



tillation is greatly on the increase owing 

 to developments in the consumption of 

 charcoal. 



In Natal, attention has been directed 

 recently to the possibility of using 

 wattle timber for destructive distillation 

 after the valuable tanning bark lias 

 been removed. At present this timber 

 is used for pit props and in other ways, 

 but the demand for it is said to be 

 much below the supply. 



Wood distillation has been under- 

 taken recently in Victoria, Austialia, 



and a large works has been opened near 

 Warburton, drawing its supplies from 

 the forests of Gippsland. 



In India also there would appear to 

 be a possibility of extending this indus- 

 try. Owing to the religious prejudices 

 of the natives it is necessary to use only 

 wood charcoal in the refining of sugar 

 intended for native consumption. This 

 and the common practice of covering 

 " go-downs " with tar-impregnated felt 

 opens out in India a market for two of 

 the chief products of wood distillation > 



PLANT SANITATION. 



MISCELLANEA: CHIEFLY PATHO- 

 LOGICAL. 



By T. Petch, b.sc, b,a. 



A disease of Tomato plants, one which 

 is most probably not new to Ceylon, 

 but which has never been previously 

 recorded, has recently been sent in for 

 examination. The plants were grown 

 from English seed, and developed nor- 

 mally until they reached the fruiting 

 stage. Some of them then began to die 

 off. Although the weather at the time 

 was excessively wet, their leaves wilted 

 just as they might be expected to do in a 

 prolonged drought. The wilted leaves 

 decayed and fell off, and finally the 

 stems decayed also. There is very little 

 evidence of disease in the stern when the 

 leaves begin to droop, but if it is cut 

 across near the base the woody part 

 immediately round the pith is found to 

 be brownish, and minute white or 

 yellowish drops of liquid ooze out fiom 

 this region. These drops consist of 

 enormous numbers of bacteria, and if 

 sections of the stem are examined under 

 a microscope, they are found to issue 

 from the vessels of the wood which are 

 completely filled by them. The vessels 

 convey the water from the roots to the 

 leaves ; and they are unable to perform 

 this function when they are plugged by 

 masses of bacteria. Hence the leaves 

 wilt because they are deprived of water, 

 although it may be raining heavily at 

 the time. In dry weather, plants 

 attacked by this disease merely dry vip, 

 but in wet weather they decay rapidly 

 owing to the rapid growth of various 

 saprophytic fungi, etc., on the moribund 

 tissues. 



The bacterium is, as far as can be 

 ascertained without elaborate bacterio- 

 logical investigation, Bacillus solana- 

 cearum. It is well known as the cause 

 66 



of wilt disease in potatoes, tomatoes, 

 and egg plants in the United States, and 

 has recently been recorded on potatoes 

 in Mysore, where it causes "Ring 

 disease." There is no treatment tor the 

 disease, except the removal and burning 

 of diseased plants as soon as they begin 

 to wilt. The bacteria live in the root 

 and the base of the stem, at least in the 

 early stages, and, therefore, the plants 

 must be dug up with the roots. They 

 must be burnt ; if they are thrown on 

 the rubbish heap they merely spread 

 the disease. As the bacterium attacks 

 many species belonging to the potato 

 family, it is a waste of time to plant 

 tomatoes, or brinjals, or cape gooseberry 

 on the same ground for the next two 

 years. Tobacco and chillies would 

 probably be attacked also. 



The root disease caused by Poria 

 hypolateritia has hitherto been recorded 

 only from estates above an elevation of 

 4,000 feet, and hence it was considered 

 purely an up-country tea root disease. 

 During the last few months specimens 

 have been sent in from new clearings in 

 the Kandy, Matale, and Kegalle dis- 

 tricts. In each case the plants attacked 

 were about two years old. The roots of 

 these plants were covered with the red 

 sheet of mycelium, or were mottled, red 

 and white, when the mycelium had been 

 injured. The fructification is rarely 

 found on old tea bushes killed by this 

 disease, but on these young plants it 

 was present in several instances ; it is a 

 thin, pinkish or reddish sheet, studded 

 with minute holes, and is always found 

 at the collar of the plant, sometimes 

 extending over the surface of the soil. 

 The full details of this disease have not 

 yet been worked out. The mycelium on 

 the exterior of the root points to a 

 spread from some jungle stump, but up 

 to the present time the fungus has not 

 been connected with any species of 



