392 



SMU 



S 31 tJ 



the bottom of the dyke ; and rather 

 project a little at each end, that 

 the passages may not be obstructed 

 by dirt or sods falling from the 

 dyke. These boxes should be 

 placed in the lowest hollows of the 

 marsh, or in the creeks, and the 

 ground well hardened beneath 

 them, and on their sides. It is | 

 better to place two or three boxes , 

 side by side, if needful, than go to 

 the expense of building a more ' 

 costly kind of sluice. And each | 

 hollow or creek, through which a 

 dyke passes, and wherever there is : 

 likely ever to be fresh water to | 

 convey away, should have one or 

 more of these little sluices. 



Each box should have a clapper, 

 or shutter. The shutter is to be 

 fastened to the mouth of the box, 

 at the end towards the sea, with 

 hinges made of iron or wood. The 

 rising tide presses the shutter close 

 to the mouth of the box, so that no 

 water can enter ; and at ebb tide 

 the fresh water, when there is any, 

 opens it by its pressure, and passes 

 out. 



When it is found necessary to 

 build larger kinds of sluices, Beli- 

 dor''s Architecture. Hijdraulique and 

 Muller, should be consulted. 



SMUT, a distemper in grain, 

 which dissolves the substance of 

 the kernel, turns it to a black dust, 

 and bu:sts the coats of the kernels. 



M. Duhamel distinguishes it by 

 its entirely destroying the germ 

 and substance of the grain ; by its 

 affecting not only the ear, but the 

 whole plant, and extending itself 

 most commonly to all the ears 

 which arise from the same root. 

 He says he has found it as early as 



Hi April, by opening a plant, and 

 taking out a young ear, not more 

 than the sixth of an inch long ; that 

 a distempered ear, when it conies 

 out ot its hose, looks lank and 

 meagre, and that the black powder 

 may be seen through the thin coat 

 of the grain ; that the powder has 

 a fetid smell, and no consistency ; 

 that it is easily blown away by wind, 

 or washed away by rain ; and that 

 he has never found it to be conta- 

 gious, like the powder of burnt 

 grain. 



M. Tillet observed that the up- 

 per part of the stalk of a smutty 

 plant is not commonly straight, 

 from about half an inch below the 

 ear ; and that in that part it is stiff 

 and hard, and is almost entirely 

 filled with pith, very different from 

 the stems of healthy plants; whence 

 he concludes, that the ascent of 

 the sap is obstructed in the stems 

 of smutty plants. 



The real cause ©f smut has es- 

 caped the researches of many phi- 

 losophers. M. Duhamel justly ob- 

 serves, that it cannot be a want of 

 fecundation, as it destroys both the 

 male and female organs, long be- 

 fore the time of fecundation. 



He confutes the conjectures of 

 its being caused by wet upon the 

 ears, or the violent heat of the sun, 

 by observing that the ears are 

 smutty before they cease to be co- 

 vered by the blades. And if it 

 were owing to the moisture of the 

 earth, he observes, that there would 

 be more smutty plants in the low 

 and wet, than in the high and dry 

 parts of a field, which is not fact. 



He adds, that he never could 

 make it appear that the distemper 



