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that will not grow in other gardens. This warmth of soil has 
been very severely tested this year. I have never taken the earth 
temperature of my garden at any time of the year, but very 
accurate records of earth temperature have been kept for many 
years at Regent’s Park, which is a cold, clayey soil. There Mr. 
Sowerby has recorded that the coldest night of the year was 
February 7—when the thermometer stood at 7°5—but on that 
night at one foot below the ground the thermometer was 31°, and 
it was not till seven days after, that the earth temperature was as 
low as 28:2, when the air temperature had been steadily rising for 
some days, and all through the winter the earth never froze lower 
than one foot. The experience of the gas and water companies 
throughout the kingdom showed that the freezing of the soil 
depended less on depth than on the situation and nature of the 
soil. It was found that pipes laid at three feet below the soil on 
an incline facing to the North would freeze sooner than pipes 
laid one foot but with a Southern aspect; and pipes laid in a 
porous light soil were much less injured than those in a hard 
and heavy soil ; and the pipes that were most injured were those 
laid under concrete. We may be quite sure that what is true of 
underground pipes is equally true of the roots of plants, with, 
however, this qualification, that the power of roots to withstand 
frost depends not only on their depth, or the warmth of the soil, 
but also on the rich or poor character of the soil. It was an old 
observation of Humboldt’s, “In general it is remarked by 
cultivators that the trees which grow in a fertile soil are less 
delicate, and consequently less affected by great changes in the 
temperature than those which grow in land that affords but little 
_ nutriment.”—Personal Narrative, vol. i, chap. 2. This seems 
natural, for it is the same in all animals; a healthy, well-fed 
man or animal can fight against cold far better than a weakly one, 
and there is a strong likeness between animal life and plant life ; 
but this year’s great frost has shown me one difference. In any 
animal, say especially man, there is a great centre of life in the 
