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the tree fails just when the production does. The prime exhaustion 

 method showed better results at the beginning of work and up to the 

 middle of August giving a far greater production than the ordinary 

 exhaustion method but the product suddenly fell at the close of August 

 while in the latter method the excretion in September is still quite 

 considerable. In the ordinary exhaustion method, the gashes being 

 fewer than in the prime exhaustion method, the excretion is slow and 

 regular but it continues longer. 



In this experiment in Kanagawa Prefecture, the trees were too 

 young being only 18-22 cm in circumference to make a perfect compari- 

 son between the two systems and these trials can only be considered as 

 preliminary to further experiments. 



A similar experiment made in 1908 in Iwate Prefecture on larger 

 trees being 63 cm in circumference produced good results in making a 

 comparison of two methods. The ordinary exhaustion method was tried 

 on 25 trees having an average circumference of 64.2 cm and they 

 produced 62,387 grams of lac. The prime exhaustion method was also 

 tried on 25 trees of an average circumference of 62 cm and they 

 produced 59,513 grams of juice. 



According to the results obtained in preliminary experiments in 

 Kanagawa and Ibaraki Prefectures in the previous year, the production 

 of lac from the rhus tree was directly proportional to the square of the 

 radius of the trunk from which it was collected so long as no abnormality 

 exists in height and circumference. This empirical formula agrees well 

 with the results shown in Iwate and the total productions of lac obtained 

 is about the same in both methods. 



Taking the best time for tapping, when a large yield of superior 

 quality is obtainable, the tapping of " Original lac " lasts 95 days in the 

 ordinary exhaustion method and only 75 days in the prime exhaustion 

 method. The lac extracted from one tree daily on these periods averaged 

 7.5 grams and 11.3 grams respectively for the ordinary and the prime 

 exhaustion methods. The daily extraction of lac by the prime exhaustion . 

 method was larger in quantity than by the other, although somewhat 

 smaller sized trees were used. It is in favor of this method that we can 

 fully extract lac in a shorter period and that the yields of " Short lac " 



