384 THE POPULAR SCIENCE MONTHLY. 



very slightly increased, and the liver is hardly more stimulated by the 

 pressure of the diaphragm and abdominal walls during the walk than 

 it would have been had the patient remained quietly at home. Time 

 is an important element in many cases. Many a hard-worked man 

 has his day so fully occupied that he can not give up more than a 

 quarter or half an hour to exercise, and it is of importance that in 

 this limited period he should get as much exercise as possible, and 

 the best way to employ this brief time is by taking horse-exercise. 

 I believe it is to the late Lord Palmerston that we owe the saying 

 that "the outside of a horse is the best thing for the inside of a 

 man," and it is very near the truth. A brisk trot for fifteen minutes 

 will cause more pressure upon, and stimulation of, the liver than a lazy 

 lounge of an hour or more. The time for this will depend in a great 

 measure upon the engagements of the patient. It should not be taken 

 immediately after a meal, and for most men whose days are fully 

 occupied almost the only time to take it is before breakfast. A cup 

 of milk, or a small cup of tea or coffee, with a piece of bread and 

 butter or a biscuit, may be taken just before starting, and then the 

 regular breakfast will be taken with greater appetite and better diges- 

 tion after the exercise is over. 



By careful attention to the removal of waste products, and to the 

 prevention of absorption of poisonous substances from the intestine, 

 by regulation of the diet, regulation of the bowels, and exercise, in 

 the ways just mentioned, I believe that the nervous exhaustion and 

 depression from which brain-workers suffer may be greatly diminished, 

 even although it may not be entirely prevented. Practitioner. 



-- 



OIL-PLANTS OF FRENCH GUIANA. 



By Dr. J. HAEMOND. 



THE flora of Guiana includes a considerable number of plants of dif- 

 ferent families whose organs contain fatty matters. The most 

 important of these plants, both on account of the abundance and quality 

 of the oil it yields, is the carapa {Carapa Guianensis, D'Aublet; X^lo- 

 carpus carapa, Spr. ; crabwood of the English), a plant of the family 

 of the Jfeliacem, the family of which the Pride of India is the best 

 known representative. It is one of the largest trees of the country, 

 reaching a height of from sixty-five to a hundred feet, and a diameter 

 of from a yard to a yard and a half. The wood is of a grayish or red- 

 dish color, and of excellent quality, is much in demand on account of 

 the ease with which it is worked, and is used for shingles, cabinet, car- 

 penter's and carriage work. The leaves are abruptly pinnate, with 

 smooth, oval leaflets about a foot long and ending in a projecting 



