This is a tree of some height, the trunk and branches of which are covered with a thick, brownish and reticulate bark. Leaves alternate, oblong, cordate, rather tomentose on their lower surface, and supported by short petioles. Flowers in tufted panicles, ramose, arising from the axil of the leaves or the extremities of the branches; they are dioïchous, with a simple, urceolate perigone having three divisions. Male flowers with six stamens, the filaments of which are attached to each other, and are inserted in a glandular disk. The female flowers are smaller, one unilocular, ovary, style wanting, stygma bilobed. Capsular berry, with two valves, containing an oleaginous seed, surrounded by an aril crenated above. This tree is found in the provinces of Para and Rio-Negro. We use the red juice which is acrid and very poisonous and is obtained by cutting into the bark. _First day._—1. Vertigo from right to left, on waking in the morning. Difficulty of swallowing the saliva. Constriction of the isthmus of the pharynx; this pain increases progressively. Pain and pressure from within outwards at the right frontal eminence. 5. This pain intermits now and then and is less in the open air. Pain in the finger-nails, with swelling of the phalanxes. Painful pinching in the right calf. _Second day._—He is unable to fall asleep in the evening, in bed. Confused dreams about houses which one is building, commencing at the upper stories. 10. The buccal cavity, the tonsils and the upper part of the pharynx are painful to contact, the soup, when chewing or swallowing it, seems to make these parts sore. Burning sensation in the throat. The urine is discharged less frequently. Dizziness, in the morning. He is indifferent and careless in regard to his business. 15. Sensation as if a foreign body, of the size of a walnut, had lodged in the interior of the left inguinal region, the whole morning. The face is highly colored. Tingling in the left thumb-joint. Stiff hands as from squeezing something in one’s hands for a long time. Pain in the left hand; thirst. 20. He swallows his saliva with less pain and more ease. The urine is scanty and discharged less frequently, though he has drank a good deal; it is of a reddish yellow. The pains in the hands increase when the hands are joined. He is in the habit of drinking two tumblers of water before going to bed, and he urinates immediately afterwards; on the second day he drinks in the evening, but does not urinate. Pinching at the right side of the neck.