1816.] 



AND HOBTIGULTURIST. 



53 



But it is a question if vapor of water is taken 

 up at all by the roots. Sachs and Knop, in their 

 experiments, found roots would not absorb, but 

 rather exhale, vapor. Free water injures the 

 roots of most plants if they are long confined in 

 it, it is true, but when drained off there is left 

 capillary and hygroscopic water, and with this 

 the plant grows in the most healthy manner. 



This is the principle of underdraining land, 

 and there is, of course, moist air in the soil, be- 

 cause it is then open, with air circulating in it ; 

 and this air, if there is sufficient water in the 

 soil, will be vioist air — so that it is true that plants 

 need moist air, but this only as a necessity from 

 having a well-drained soil with water in it, not 

 bottom water, but capillary and hygroscopic. 



So keep the hole open in the bottom of the 

 pot and let the plants have a chance to have 

 moist air, but do not keep the soil as an old lady 

 of my acquaintance advised — " a muddy wet." 



Wliile the' editor saj's we want moist air in the 

 soil, not water, I say we want moist air in the 

 soil and water, and the water furnishes nearly 

 all the food of the plant, save carbonic acid. 



For the highest authority in the world on this 

 subject, I refer the reader to " How Crops Feed," 

 by Prof. S. W. Johnson, pp. 36 and 200. 



[We do not know that we have any objection 

 to make against this statement. We are reminded 

 of the good minister who objected to dancing, 

 but who was opposed by a gay young parishioner 

 who thought she had Scripture to justify her, 

 and she quoted that " David danced before the 

 ark." " Ah ! " quoth he, " David danced singly 

 and alone. If you want to dance as David did, 

 go on." Now, there is water in every thing. In 

 every one hundred pounds of wheat flour there 

 is sixteen pounds of water, but it appears quite 

 dry to us, and we suppose there is no earth that 

 the gardener ever handles so dry but contains 

 "water." But the water we refer to is of another 

 kind. Wet and dry, horticulturally, are techni- 

 cal terms. To the gardener, when the earth 

 "smears" — makes a paste when he presses it — 

 it is wet, contains water ; when it rather powders 

 under pressure, it is dry to him. There is water 

 there, of course, in a chemical sense, but ^not in 

 the horticultural one. — Ed. G. M.l 



THE POTATO DISEASE. 



BY M. 



Permit me to make a few remarks in answer 

 to your and Mr. Worthington Smith's conclusions 



respecting potato rot. You are aware, I suppose, 

 of the very marked difference between the old 

 potato rot of 1846, '47 and '48 and what is termed 

 the potato blight of to-day. The rot commenced 

 with the potato, the blight with the leaf. In 

 1848, in Ireland, potatoes rotted everywhere, 

 with one exception, and that was where they 

 were put in ridges by the spade. Those ridges 

 were generally from five to seven feet wide, and 

 I was assured by a correspondent that wrote me 

 at the time that while the potatoes in the centres 

 of the ridges always rotted yet the rows upon the 

 brows of the ridges, alongside the trench, where 

 no water could lie, were always sound and good. 

 In those days, in this country, I could tell by 

 the thermometer what prospect we had for a 

 crop of potatoes. If we had a succession of warm, 

 showery w'eather in August, so much that the 

 water would lie between the rows, and when 

 tried by the thermometer it would stand from 80 

 to 85 degrees, and this state of weather continued 

 for three or four days without dry, windy weather 

 setting in, so as to absorb the heated moist- 

 ure the potato was enclosed in, the crop was 

 gone. If the weather blew up suddenly dry, only 

 such potatoes as the water sat around would go 

 to rot. All others were safe. Many is the stalk 

 of potatoes that I have pulled up, and always 

 found the points of such potatoes as were imbed- 

 ded in the heated moisture going to decay. I 

 have spread many and often stalks of potatoes 

 partially rotted along the tops of the rows to dry, 

 and always found that as soon as perfectly dried 

 that the rot extended no farther, and that such 

 portions of potatoes kept perfectly sound during 

 winter. Such was potato rot ; but potato blight 

 is a horse of another and very different color. It 

 attacks the leaves and tender tops. I have never 

 seen the appearance of a more promising crop of 

 potatoes in Ireland than was last year until, one 

 day a cold, chilly fog came floating along, and 

 which was so cold thf(t by the next morn potato 

 leaves were frozen stiff, so that as soon as the 

 sun came out upon them they began to blacken 

 and afterwards to smell, destroying all the late 

 crop. Now, what was it that killed thos$ potato 

 tops? — for at this time examine the tubers and 

 you can notice nothing wrong with them. Mr. 

 Worthington Smith says that it w^as fimgus. The 

 conclusion that I came to was that a frost that 

 would freeze a tomato, a snap-bean or a potato 

 stiff vf as enough to kill them without asking any 

 aid from a fungus to help. A few days later— 

 26th of August— I sailed from Rothsay, Isle of Bute, 



