EDITORIAL. 



THE EFFECT OF LITSEA CHINENSIS ON THE HARDENING 

 OF LIME MORTAR. 



The leaves of the plant known to the Tagalogs as puso-puso {Litsea 

 chinensis Lam.) have long been in favor with native masons for use in 

 making mortars. Their present method of treating the leaves of the 

 puso-puso for this purpose is to beat the fresh leaves into a pulp, 

 adding water until the mixture is a pale green. This is rather sticky 

 and becomes more so as it ferments. After it is thus prepared it is 

 allowed to stand and ferment for from twelve to eighteen hours, when it is 

 used with native lime. 



Undoubtedly these leaves have been employed for this purpose for a long 

 time as Blanco^ tells us that puso-puso is well known in the Philippines, 

 the leaves when infused in water for six or eight hours forming a 

 mucilaginous substance, they being cut into small pieces with a knife 

 and triturated very well before being put into the water. When the 

 decoction is mixed with lime and sand it is stated that a very strong 

 mortar is made which is said to be almost impermeable to rain. 



The puso-puso is a tree 7 to 9 meters high with a very hard wood. It 

 is a species widely distributed from southern (tropical) Asia to Malaya. 



Governor Sandiko, of Bulacan Province, reports that the native masons 

 make their cement of lime 30 parts, sand 60 and melaza 1 part ; the water 

 used being the puso-puso Juice prepared as above described. 



Mr. Warner, of the Bureau of Supply, using the puso-puso decoction 

 and comparing its results with those obtained with lime and sand mixed 

 with water alone obtained the following table. In all the tests 18;J per 

 cent of water, respectively, puso-puso solutions were used. The tensile 

 strengths are as follows : 





Time of set. 



Average. 



One 

 month. 



Two 

 months. 



Three 

 months. 



One 

 month. 



Two 

 months. 



1 

 Three 

 months. 





38 



60 



88 











37 

 •37 



62 

 60 



90 

 87 



36? 



60} 



88;- 







35 



61 



88 



1 









[ *^ 



53 



77 











50 



55 



82 









Llme-sand-melaza-puso-puso juice ._ 



50 

 49 

 50 



56 

 61 

 56 



81 

 90 

 81 



491 



66J 



82; 



•Blanco, Flora de Filipinas, 2d ed. (1845), 566. 



409 



