THE SECRETARY'S PORTFOLIO. 321 



illustrate the mun's meanness; but if he was mean it was a meanness tlmL 

 benefited his patients, If men were wise they wonKl spend two days in a vine- 

 yard or orchard to every five minutes in a drug-store when anything is tfce 

 matter with them. If you have dyspepsia, eat fruit. Did you ever tliink wh«:i 

 a doctor gives for dyspepsia ? He gives an acid. Fruit will furnish a bet^^er 

 acid than the drug-store will. Do you know what the doctors dose you wi<Jk. 

 when your liver is out of order ? With acids. Then why not supply tHe 

 remedy yourself from your own garden ? Why continue to have your medi- 

 cine done up in such a repulsive mixture when nature furnishes it in so palata- 

 ble a shape. 



DEAD BRANCHES DETRIMENTAL. 



Prof. C. E. Bessey, in the New York Tribune, takes the ground that dea£. 

 branches upon a tree are detrimental to its health and growth ; arguing froisL 

 the now acknowledged fact that the escape of water from the leaf does nxst 

 differ in any way from the evaporation of water from any other moist surfarat,. 

 he says : 



A leaf is a mass of cells, every one of which is gorged with watery matta::, 

 which in a dry atmosphere, as a matter of course, tends to escape. Tfce 

 epidermis, composed of dryish, impervious cells, which entirely surrounds tfeE. 

 watery cells of the leaf, would prevent almost completely the evaporatioE «{! 

 water from the latter were it not for the breathing pores before meutionoL 

 These pores are for permitting the free ingress and egress of gases, particularly 

 oxygen, carbonic acid, and probably, also, ammonia. Now, when the pores are 

 open for their legitimate purpose it happens that more or less water escapes, k' 

 the air is dry. If the air happens to be very moist, the loss of water througi. 

 the breathing pores is very little or even none at all. 



We may put it in this way: The leaf loses water simply because it is a waterf 

 structure; its epidermis is designed to prevent this loss, and the breathiiig- 

 pores with their power of opening and closing are for the sanje purpose. £. 

 leaf instead of being an organ of evaporation is actually a structure in whi<^ 

 evaporation is quite successfully checked. Careful experiments made und-ec 

 my supervision in the Iowa Agricultural College in 1880 by Miss Ida Twit chel!l< 

 a graduate student, demonstrated that the evaporation from a moist piece «sC 

 dead wood was exactly like that from a living leaf. Now when a dead bran^dr. 

 is large enough to keep continually moist in the interior it will in dry air coc- 

 stantly lose water by evaporation from its surface. This water so lost is tat-es- 

 from the tree, and must have been supplied directly or indirectly by the liviag; 

 portions. Moreover, it must be remembered that a living branch is well pp»- 

 tected against loss of water through evaporation, by the epidermis which cove^nE 

 all its surface wiien young, or the impervious corky bark which is always fouRC 

 on it when older. When a branch dies, these protecting devices soon fall ifito 

 decay and the water, so carefully guarded by the living parts of the piant,«; 

 wasted by evaporation. 



41 



