JAfe and Writings of Theodore de Saussure. 25 



the degree of desiccation the cereals might undergo, without 

 being deprived of the power of germination, and to know whe- 

 ther, after the commencement of vegetation and a subsequent 

 desiccation, the seed was killed. This investigation Theo- 

 dore de Saussure undertook. He dried seeds in a stove, and 

 made them sprout in moist sponges. Twenty species of cereals 

 and other seeds, selected from the most important kinds, were 

 submitted to this trial. He found that the greater part of the 

 alimentary seeds germinated preserve their vegetative power 

 after the greatest degree of drying they can be subjected to in 

 the open air, in the shade, or under a temperature of 35°. 

 Such was the case with wheat, rye, barley, maize, lentils, cab- 

 bage, lettuce, buckwheat, &c. The bean, the kidney-bean, and 

 the poppy, have not the same property. 



In some germinated seeds, the vegetative faculty is pre- 

 served even after a drying carried to the temperature of 70° C. 

 (158° r.) the strongest heat that the sun can communicate to 

 the soil in our climates ; and this property, fortunately, belongs 

 to the most important of these grains, wheat and rye. 



A seed germinated and dried requires, in order to regain 

 the humidity it needs, at least the same time which would 

 have been necessary for germination in its normal state. This 

 time is so much the longer the more germination is advanced, 

 and this explains why seeds which putrefy easily, such as the 

 kidney-bean and the bean, are destroyed before regaining the 

 humidity requisite for a second vegetation. 



The dry germinated seeds, however short a time the germi- 

 nation may have been prolonged before desiccation, lose their 

 rootlets in the repetition. The seedlings, thus reduced to a 

 kind of slip, have necessarily a less vigorous vegetation than 

 if that vegetation had been exposed to no interruption. 



No grain germinated and dried shewed symptoms of germi- 

 nation after an interruption of more than three months. 



A considerable artificial drying, produced by keeping the 

 seeds in a vacuum, and introducing under the receiver a 

 capsule full of sulphuric acid, did not deprive any kind of seed, 

 at the atmospheric temperature, of the power of germinating ; 

 commonly, however, the seeds require a longer moistening. 



Among the germinated seeds subjected to the same artificial 



