38 



If adopting the alum the caps cannot be made of iron, nor of 

 any metal attached thereby, neither can "tapping" be done with 

 a steel instrument, because it blackens the product. 



Also the form and material in which they have to be manufac- 

 tured differ, when they are destined for use on the branches they 

 must be made of light material if they are for the roots then they 

 may be made of heavy stuff. 



According to the above, we must use for the extraction of the 

 milk from the roots, cups of raw clay, which although they im- 

 prove the product, still are liable to crack and allow part of the 

 milk to escape, and deposit itself in the soil. 



For the use of extraction by the roots, the best cups or basins 

 should be those of clay baked and glazed inside, which stops 

 the filtering through of the water or solution employed. They 

 should affect the form of a semi-circumference, ten centimetres in 

 diameter [4 inches] offering the greatest surface at the part which 

 has to remain adherent to the root to permit of several cuts being 

 made. To where the cups or basins adhere perfectly to the root 

 it is necessary at the point of junction, to place clay plaster to 

 fasten the cups to that part. 



The cups can be made of zinc sheet. A cow's horn can also 

 be used. The cups for the extraction from the branches should 

 be as deep as a glass. 



We will now treat of a part no less important. — knowing the 

 mean production from a tree in a wild state, and advantages of 

 culture of Manicoba. 



MEAN PRODUCTION OF RUBBER PER TREE. 



Collecting carefully and separately the production obtained 

 from fourteen trees, was found to give the mean of 5773 grains per 



plant. 



Afterwards taking another production of ten trees the mean 

 was 77' 1 5 grains, per plant. 



We found one tree whose production taken by itself attained 

 1197*50 grains. 



According to these results obtained under the irregular con- 

 ditions of the dry and bad season, it is seen that the mean is not 

 disappointing, it should also be noticed that those trees submitted 

 for the test, in the majority had already suffered from previous 

 tappings. 



PRODUCTION OF A TREE IN ITS WILD STATE UNDER NORMAL 



CONDITIONS. 



Taking into consideration the dry and bad seasons and the 

 losses in the extraction, it may be safely estimated at 100 grains 

 the mean of production of one tree in its wild state, during the 



time it is undergoing tapping. 



****** 



THE MANICOBA AS PRODUCER OF FORAGE. 

 The seeds constitute a food, liked by cattle, and of great ali- 



