cyanogen acid, similar to Mandioca, coagulating rapidly under 

 the action of oxygen, light and heat ; it dries leaving on the 

 bark a transparent layer which is easily detached in ribbon-like 

 form, forming an excellent rubber. In mixture with water it 

 coagulates in two parts, one solid, forming caoutchouc, or rubber; 

 the other in suspension with it, giving it a milky colour, and con- 

 sisting of albuminoid and other substances. 



The milk ferments quickly ; this we believe is clue to the al- 

 bumen, and giving off a smell of sulphydrate of ammonia, leav- 

 ing the rubber intact, which gradually loses its colour through the 

 development of the fermentation. 



THE MOST APPROPRIATE TIME FOR TAKING THE MILK. 

 It is necessary to study the best time for tapping from four 

 different points of view, principally : — 



1. To obtain the greatest quantity of the product. 



2. Not to damage the plant for future production. 



In all the plants the circulation takes place with more or less 

 activity in accordance with the seasons and the local climate. 



in cold climates ihe sap remains paralyzed during the winter 

 season. In hot and clamp climates the sap is always in activity, 

 increasing the circulation as the temperature rises, through the 

 accumulation of the vapours in the atmosphere. 



In hot and dry climates, part of the year the sap lies paralyzed 

 on account of the liquid necessary to serve as a vehicle to the 

 principal nutritives. 



In our country we look upon two principal zones for the culture 

 of Manicoba, one hot and dry, the other hot and damp. 



m the first, the circulation of the sap becomes active from 

 October forward until April. 



In the second, in spite of the rains in June, the activity takes 

 place from September to January, the storm season. 



It is in this season therefore, that the ascending movement of 

 the sap takes place in the Manicoba with all activity, carrying in 

 the solution the principles which, on reaching the leaves have to 

 endure the action of the oxygen so that after they are elaborated, 

 they descend, renovating and creating new tissues, surcharging 

 itself with the principles in excess, which are naturally expelled 

 through the bark by ruptures or by the attack of insects. There- 

 fore after one or two months the plant is replete with sap and 

 with milk. 



BEST TIME FOR COLLECTING. 



The best time to commence taking " in the hot and dry zone" is 

 between October and April, when the plant is in full vigour, and 

 rich in " elaborate" principles establishing by the extraction of 

 milk as if a continuous action were taking place by the defalca- 

 tions and obliging the plant to refill this want, absorbing new ele- 

 ments and encountering with soil the water necessary for this 

 substitution. This cannot take place from May to October, in 



