SALTS. 



severa. v et days occur, the rain of the first 



must contain more of it than the second. The 



rain of a thunder-storm, alter a long-protracted 



... . ...,,.. i\,r ihii rayon, u> i-.nuun tin- 



which is conveyed to the 

 earth at one time. But all the analyses of 

 atmosphrnc air kukerto madt hart failed to de- 

 monstrate the presence of ammonia, although, 

 Minimi 1 1 1 to our view (says M. Liebig), it can 

 never be absent. If a pound of rain-water con- 

 ly one-fourth of a grain of ammonia, 

 thro a n>ld ul 40,000 square feet must receive 

 annually upwards of 80 IDS. of ammonia, or 65 

 Iba. of nitrogen; for, by the observations of 

 Bdmblrr. which were formerly alluded to, 

 about 700.000 IDS. of rain fell over this sur- 

 4 months. This is much more nitro- 

 gea than is contained in the form of vegetable 

 albumen and gluten in 2660 Ibs. of woad, 2800 

 Ibs. of hay, or 200 cwt. of beet-root, which are 

 the yearly produce of such a field ; but it is 

 lesa than the straw, roots, and grain of corn 

 u hirh might grow on the same surface would 

 contain. Experiments made in the laboratory 

 ah the greatest care and exact- 

 hare placed (coiitmurs Liebig) the pre- 

 of ammonia in rain-water beyond all 

 It had hitherto escaped observation, 

 because no one thought of searching for it." 

 See ANMOSIA. 



I cannot recommend the farmer to adopt the 

 able conclusions of M. Liebig without consider- 

 able caution : hardly any thing retards the pro- 

 gress of science more than erroneous theories. 

 Fortunately, however, the farmer can in all 

 eases patiently and successfully examine and 

 apply the valuable facts of the skilful chemist 

 mystifying himself with not always in- 

 telligible doctrines. It is very probable that 

 plant?, have the power of decomposing ammo- 

 nia, and of assimilating: the nitrogen which it 

 contains in the same way as there is little 

 doubt the hydrogen of water is assimilated by 

 them ; but we have no direct evidence of the 

 fact", and the best course, therefore, will be to 

 regard them not as absolute chemical truths, 

 <he class of what may be per- 

 haps denominated scientific probabilities. 



Some of the other compounds of chlorine, 

 the old class of chlorides of the chemist, have 

 tried as fertilizers, with very doubtful 

 although at first the seeds which 

 steeped in them germinated with a 

 considerably increased rapidity, yet they speed- 

 fly seemed to suffer by this additional stimu- 

 lu. Davy tried solutions of chlorine, and sul- 

 phate of iron (jfreen vitriol) : he says, "Though 

 the plnme was very vigorous for a time, yet it 

 became at the end of a fortnight weak and 

 sickly, and at that period less vigorous in its 

 growth than the radish sprouts which had been 

 naturally developed, so that there can be 

 scarcely any oseful application of these expe- 

 riments. Too rapid growth and premature de- 

 cay seem invariably connected in organized 

 structures, and it is only by following the slow 

 operation* of natural causes that we are capa- 

 makinj? imp ovements." Oxymuriate 

 of lime. or. properly speaking, chloride of cal- 

 however, appears to be beneficial to 

 vegetation : this was ascertained in 1795, by 



SAMPLE. 



Ingenhouz ; and I have given in my work On 

 Fertilizers, p. 367, the result of some trials by 

 Mr. Finchamwith this chloride that were highly 

 successful: he says, "Half of some turnip- 

 seed were steeped for 36 hours in a solution 

 of chloride of calcium, composed of 1 part 

 chloride of calcium, and 48 parts water ; this 

 was sown under precisely similar circum- 

 stances of soil and aspect with the other half 

 unsteeped. The first came up much sooner, 

 was never attacked by the fly, and the produce 

 was half as much again, arid the tops made 

 more luxuriant. He attributes the failure of 

 Davy to his having used the chlorine, uncom- 

 bined with the base lime. 



Mr. Owen Mason, of Providence, Rhode Island, 

 has computed the saline contents of the crops 

 raised from a field near that place, during 8 

 years' cultivation, as follows : 



Potash 

 Soda . 

 Lime . 

 Magnesia 

 Alumina 

 Silica . 



Ibs. 



424-92 

 131-92 

 532-88 

 . 64-08 

 . 5-96 

 390-40 



Ibs. 



Sulphuric acid 113-88 

 Phosphoric acid 108-12 

 Chlorine . . 58-64 



Total 



1830-80 



' It is doubtful," Mr. Mason observes" " if 

 the cultivator ever suspected that he carried to 

 his barn two casks of potash, one cask of soda, 

 two casks of lime, a carboy of oil of vitriol, a 

 large demijohn of phosphoric acid, and a variety 

 of other matters contained in his fourteen tons 

 of fodder, which were as certainly stowed away 

 n his mows as if they had been conveyed thither 

 n casks and carboys." This statement will per- 

 haps serve to give some idea of the enormous quan- 

 tities of saline matters that are removed from the 

 soil by the crops ordinarily raised. When the 

 crops are eaten on the farm, and the manure pro- 

 duced therefrom is returned to the soil, there is 

 established a continued circulation of those ingre- 

 dients which would be lost if the crops were re- 

 moved and the stock sold. See SOILS. 



SALTPETRE (Germ, and Fr. salpetre). See 

 NITRATES and SALTS. 



SALTWORT (Salsola, from salsus, salt; in 

 allusion to the saline properties of the species). 

 A genus of plants which inhabits the sea-coast, 

 especially abundant on the coast of the Medi- 

 terranean, where they are extensively gathered 

 and burnt for the manufacture of barilla and 

 soda. See KELP. 



SALT-MARSH CATERPILLAR. See CA- 

 TERPILLAR. 



SALVING or SMEARING sheep is resorted 

 to in various districts, for the purpose of pre- 

 serving the fleece from the effects of weather, 

 destroying injurious insects, and preventing 

 cutaneous diseases. A mixture of damaged 

 butter, hog's lard, resin, and Gallipoli oil, is 

 found to be the most efficacious salve. Tar 

 stains and spoils the colour of the wool. See 

 SHEEP. 



SAMPLE. A small quantity of a commodity 

 exhibited at public or private sales, as a speci- 

 men. Wool, wine, corn, seeds, and indeed 

 most species of agricultural produce and mer- 

 chandise that can be conveyed in small bulk, 

 I are sold by sample. If an article be not at an 

 j average equal to the sample by which it is 

 sold, the buyer may cancel the contract, an 



