1834.] Scientific Intelligence. 1 5 1 



they repelled, plants of wheat were placed in the water. They lived well ; the 

 yellow colour of the fluid became less intense, the residuum less considerable, and 

 it was evident that the new plants absorbed a portion of the matter discharged by 

 the first. Hence the practice of cropping wheat after beans is justified by this 

 experiment. 



Wheat, rye, and barley were subjected to experiment. They do not live well 

 in pure water, probably from the quantity of mineral substances, particularly 

 silex, which they contain. The water in which they vegetated was clear, trans- 

 parent, without colour, smell, or taste. It contained some salts, alkaline and 

 earthy muriates and carbonates, and only a very small portion of gummy matter. 

 As gummy matter appears to be a good preparation for wheat, which was il- 

 lustrated in the experiment of the bean, corn-crops which do not give out gummy 

 matter, ought not to succeed each other. And as M. Macaire thinks that plants 

 of corn reject scarcely any thing but the saline matters foreign to vegetation, it is 

 probable that any preparation but by their own kind, would be acceptable to seve- 

 ral plants. The practice of preparing soil for corn-crops, by the culture of green- 

 crops, is thus countenanced by experiment. 



The potatoe lives well in water, and puts forth its leaves. The water is scarce- 

 ly coloured, leaves little residuum, gives but little taste, and induces the belief 

 that this is one of the plants whose roots secrete little or nothing of a decided 

 character. This experiment of the potatoe, M. Macaire observes, was made upon 

 a plant at an early stage of development. Experiment would lead to the inference 

 that the potatoe is not a very good preparative for corn-crops, which is known to 

 be the case in practice, unless it is assisted by an extraordinary quantity of manure. 

 All these facts tend to prove the theory of rotation suggested by M. De Candolle. 



We hope the chemists of our country will prosecute these interesting investi- 

 gations of M. Macaire ; and we beg to suggest the following course to be pursued. 



Let wheat, barley, and oats, be each subjected to a separate suite of experiments. 

 Let it be ascertained whether the potatoe or the turnip affords the best nourish- 

 ment to the succeeding corn-plants. Experience indicates the turnip as the best. 

 Then determine which of the three corn-plants will best follow the potatoe and 

 turnip respectively. Experience prefers Mheat after the potatoe, and barley after 

 the turnip. The oat is not a favourite after either. Let red and white clovers 

 and rye-grass collectively, be tried after all the corn-plants. Experience points 

 to barley as the best nurse for these grasses, as they may be termed, according to 

 ordinary phraseology. Let it be also ascertained whether the potatoe or the tur- 

 nip is the better preparative for the grasses. Experience is partial to the turnip- 

 Then let it be determined for which of the corn- plants the grasses make the best 

 preparation. Experience decidedly says the oat. It may be proper to try the 

 grass-plants singly, and from one to three years old. We presume the value of 

 the bean and the pea has been already sufficiently ascertained by M. Macaire. 

 Should any eminent chemist direct his attention to this interesting subject, we shall 

 be happy to insert the details of the experiments. — Quarterly Jour, of Agriculture. 



We can but repeat the injunctions and the offer of the Editor of the London 

 Journal of Agriculture, should any of our friends be inclined to pursue the 

 inquiry in this country. The effects of the mixed crops, to which the natives are 

 so partial, would be a fertile subject for investigation. — Ed. 



