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and, consequently, of germinating ; yet 

 they will frequently germinate if soaked 

 in an aqueous solution of chlorine — a 

 gas which has the power of attracting 

 liydrogen from water, and others of its 

 compounds, and releasing the oxygen, 

 doing so in the case of seeds within 

 their integuments, as well as without- 

 side. Humboldt and Saussure have 

 also shown that the application of chlo- 

 rine to seeds accelerates its germina- 

 tion ; and Cress seed, which under or- 

 dinary circumstances requires some 

 days to complete the process, they 

 found effected it in no more than three 



ant phenomena, — but we can penetrate 

 the mystery no farther. 



I have never been able to discover 

 that light has injurious influence over 

 germination, and in those experiments 

 apparently proving the contrary, due 

 care was not taken to prevent the seed 

 being exposed to a greater degree of 

 dryness as well as to light. 



If seed be placed on the surface of a 

 soil, and other seed just below that sur- 

 face, and care be taken to keep the for- 

 mer constantly moist, it will germinate 

 just as speedily as the buried seed, and 

 f exposed to the blue rays only of the 



hours. The late Mr. George Sinclair, [ spectrum by being kept under a glass 

 author of the excellent Hortus Grami-', of that colour, ^ven more rapidly. 

 neus Woburnensis, also informed me | Therefore the object of sowing the seed 



below the surface, is for the purposes 

 of keeping it in a state of equable and 

 salutary moisture, as well as to place 

 the radicle iu the medium necessary 

 for its growth into a root, immediately 

 it emerges from the integument of the 

 seed. These facts hold out some bea- 

 cons worthy of being attended to, as 



that he employed chlorine with sin 

 gular success. He obtained it by mix- 

 ing a tablespoonful of muriatic acid with 

 a similar quantity of black ox de of man- 

 ganese, and half a pint of water. After 

 allowing the mixture to remain two or 

 three hours, the seed is to be immersed 

 in the liquid for a similar period, and 



then sown. Another, and I consider ! guides for the operation of sowing, 

 the most eligible mode of applying the ! They point out that every kind of 

 chlorine was also suggested to me by | seed has a particular depth below the 



the same distinguished horticulturist. 

 In this way he said he made tropical 

 seeds vegetate which refused to germi- 

 nate by other modes of treatment. He 

 placed the mixed ingredients mentioned 

 above in a glass retort, inserting its 

 bulb in the hot-bed, and bringing its 

 beak under the pot in which the seeds 

 were sown, connecting it with the 

 draining aperture of the pot. The chlo- 

 rine gas is gradually evolved, passing 



surface at which it germinates most 

 vigorously, as securing to it the most 

 appropriate degree of moisture, of oxy- 

 gen gas, and of warmth. From a quar- 

 ter of an inch to two inches beneath 

 the surface, appear to be the limits for 

 the seeds of plants; but they usually 

 vary for the same seeds in different 

 grounds and countries. It must be the 

 least in aluminous soils and dry cli- 

 mates. In general, sowing should be 



through the earth of the pot to the seeds, performed in dry weather, especially 

 with more or less rapidity, according ' on heavy soils, not only because of the 

 to the heat employed. This absolute i greater saving of labour, but because 

 necessity for the presence of oxygen is j it prevents the seed being enveloped 



a reason why seeds will not germinate 

 if buried beyond a certain distance from 

 the earth's surface ; and why clayey 

 soils often fail of having a good plant, 

 an impervious coat of the clay envelop- 

 ing the seed, and preventing the air's 

 access. How oxygen operates in aid- 



with a coat of earth impermeable by 

 the air, " which," says Sir H. Davy, 

 " is one cause of the unproductiveness 

 of cold clayey soils." Perhaps the 

 time at which any ground may be 

 raked with the greatest facility is as 

 good and practical a criterion as any 



ing the seed to develope the parts of the I to judge when it is fit for sowing. In 

 embryo plant, we cannot even guess — general, if clay does not predominate 

 •we only know that most seeds have I in its constitution, a soil rakes best just 

 more carbon (pure charcoal) in their [ after it has been turned up with the 



composition than other parts of their 

 parent plant; that the oxygen absorbed 

 bv the seeds combines with a portion of 

 that carbon, and is emitted in the form 

 of carbonic acid. These are the attend- 



ipade. If clay does predominate it 

 usually rakes with most facility after it 

 has been dug two or three days, and 

 then immediately after a gentle rain. 

 But it is certain that the sooner seed is 



