56 



Circular Note No. 18. 



A few instructions for the use of "Watt's Asphyxiator, or 

 the machine introduced for the purpose of destroying 

 the nest of the " Parasol Ants." 



1st. Clear all bush, grass, etc., from the neighbourhood of the nest and take 

 note of the prmcipal entrance. 



2nd. Pro^ide sulphur, brimstone, or sulphur paper, and a small supply 

 of charcoal. 



3rd. Place the charcoal in the combustion chamber and set it on fire, in the 

 meantime turning the wheel of the fan. Now place on the top of the charcoal 

 the fire-clay saucer, and as soon as this is hot throw in the sidphur, and insert 

 the nozzle of the machine into the main entrance securing it with a little moist 

 earth, then commence turning the wheel rapidly first seeing that the driving 

 cord is sutficiently tight to turn the shaft or spindle of the blower. 



4th. Do not cover any hole mitil the smoke has issued from it for a few 

 seconds ; when each in succession should be closed in qiiite tightly with soft 

 earth or clay. 



5th. Continue the blowing until the further points of the nest have been 

 reached, then close up the main entrance and leave for a few hours. It is 

 unnecessary to dig out the nest. 



6th. If it is found that some of the ants were not at home, successive appli- 

 cations must be made until all are destroyed. 



7th. The fire-clay pan should always be used to prevent waste of the 

 sulphur. 



8th. In walls or buildings it is better to use cement or mortar to stop the 

 holes instead of earth or clay. 



9th. The machine should be kept well cleaned, oiled, and painted with red 



lead to preserve the iron. 



J. H. HART, r.L.S., 



27th March, 1895. Supt. Royal Botanic Gardens. 



Circular Note No. 19. 



Primary Cacao Shade. 



In Bidletin No. 19, p. 4, 1893, I wrote as follows in describing the plant* 

 used for shading the Cacao tree in Nicaragua. The primary shade is formed by 

 a shrub belonging to the Compositje known as " Carrisso" probably a "Glibadium." 



Of this shrub I brouglit back with me from Nicaragua m 1893 in a case 

 with Cacao plants, three rooted cuttings, one of which was cultivated for the 

 purpose of producing flowers and seeds ; while the others were reserved for 

 propagating purposes. 



In February of this year the cultivated plant produced its first flowers, 

 and I received its determination from the Kew authorities during the present 

 month (April). 



It proves to be Eiqmtorium populifolhim H.B.K., a plant indigenous to the 

 region between South Mexico and Panama. It is used in Nicaragua as a primary 

 shade plant for cacao and grows freely from cuttings 6 inches to 1 foot long 

 made from the stem of the plant (with or without leaves) placed in the open 

 ground. The plant grows some 12 or 15 feet in height and would be a useful 

 substitute in Trinidad for the "Moko" or " Jumbi " Plantain for shading 

 purposes, l)ut it has at present no known economic value other than for this 



