REVIEWS 709 



posLire to the air. Some workers are susceptible to poisoning, result- 

 ing in inflammatory swellings, from a volatile oil which the varnish 

 contains. An antidote is said to be an infusion of teakwood. The 

 addition of ferric oxide also stops this action and increases the drying 

 capacity of the varnish. Stirring in shallow, open vessels also liberates 

 the oil. 



The yield varies widely ; a crooked tree with scant foliage often 

 yields well, while large trees may yield little. An estimated annual 

 yield for a tree with 5-foot girth is given as about 15 to 20 pounds. 

 On page 103 the statement (from Brandis) is made that one man col- 

 lected from 146 to 182 pounds (40-50 viss) per season — that is, he 

 made and cared for 1,200 scars, 200 per day. Again, on page 117, it is 

 stated by the writers that a good workman should be able to gather 

 360 pounds (100 viss) a year while superintending 500 notches, or 

 about 200 trees. The monopoly for the collection of gum on Govern- 

 ment areas is sold annually. The total yield from the Government 

 forests is about 200 tons per annum. The approximate cost, before the 

 war, of landing one ton of the varnish in England was about £64. 



The chief use of the oleo-resin is for Burmese lacquer-work, an in- 

 dustry in which some 7,000 people are engaged. This is discussed at 

 some length. The oleo-resin is also used as an indoor and outdoor 

 varnish. Wood treated with this coating, presumably because of its 

 hard surface, is thought to be resistant to termites, fungi, and teredo. 

 (Experiments to verify this are under way.) It is further used for 

 calking boats and gives a desirable surface for objects to be coated with 

 gold leaf. This varnish is little known in Europe and attempts to in- 

 troduce it have met with little success ; for, though free from certain 

 acrid and irritant properties of the Japanese varnish and resistant to 

 strong alkalies and acids, the length of time and the manner of drying 

 required are causes of complaint. Slow drying in a relatively cool, 

 dark, damp place is needed. Studies on the chemical nature of the 

 oleo-resin (Indian Forest Record, Vol. I, Pt. IV, 1909) are cited and 

 the results and recommendations from some more recent work by the 

 authors given. This includes recommendations to avoid iron tools and 

 vessels, dust and sesamum oil (substitute linseed). The stirring prac- 

 ticed by the Japanese, to make the varnish homogeneous and free from 

 the volatile poisonous oil, is advocated; also the tapping of the lower 

 parts of the tree. Ferric oxide was used successfully as an agent to 

 improve the drying capacity of the varnish, but it somewhat dulls the 

 finished surface. Turpentine or Boszvcllia scrrata oil may be used suc- 

 cessfully for thinning, but they do not increase the drying properties. 



