Medicinal plants, as the castor-oil plant and aloe, come to perfection without culture; and coffee, indigo, cotton and tobacco are also of spontaneous growth.
From this and other evidence it has been shown that the first thin shower in open vessels is produced by the accidental presence of tiny crystals obtained from the dust of the air, while the second dense shower marks the point of spontaneous crystallization, where the decrease in total available energy caused by solidification becomes greater than the increase due to the large surface of contact between the liquid and the potentially existing multitudinous small crystals of the shower.
The story of the loves of Lancelot and Guenevere, as related by Chretien, has about it nothing spontaneous and genuine; in no way can it be compared with the story of Tristan and Iseult.
About the beginning of the 10th century, however, the view was promulgated that the spontaneous production of helium from radium may be an instance of the transformation of one element into another.
Thus from spontaneous aggregations of casual aggregates, which suited each other as if this had been intended, did the organic universe originally spring.
In the region of poetry Herder sought to persuade his countrymen, both by example and precept, to return to a natural and spontaneous form of utterance.
His researches from 1860 and onwards on the then vexed question of spontaneous generation proved that, in all cases where spontaneous generation appeared to have taken place, some defect or other was in the experiment.
The spontaneous play of this sympathy he treats as an original and inexplicable fact of human nature, but he considers that its action is powerfully sustained by the pleasure that each man finds in the accord of his feelings with another's.
The odes which he published at the age of twenty, admirable for their spontaneous fervour and fluency, might have been merely the work of a marvellous boy; the ballads which followed them two years later revealed him as a great poet, a natural master of lyric and creative song.
We have here, therefore, a perfect example of acclimatization by means of a spontaneous constitutional variation.