TRANSACTIONS OK THE SECTIONS. ]0I 



a mixture of the finest plaster of Paris and water, made about as 

 thin as milk, or by coating the parts of the plant carefully with this mix- 

 ture by a camel-hair brush : the plant on drying within this thin shell 

 of plaster is easily detached, leaving the forms of the stamina, pistils, 

 and petals in their natural position, with very little change of colour. 

 Flowers thus preserved retain their peculiar odour for years, from which 

 last circumstance it appears probable that this mode of drying vege- 

 table productions would be found very valuable if employed for medi- 

 cinal plants, roots, or fruits. 



On the Longevity of the Yew, and on the Antiquity of Planting it in Church" 

 yards. By J. E. Bowman, Esq. 



Being curious to ascertain how far the reputed longevity of the yew 

 would be sustained by an examination of the annual rings of its trunk, 

 and how far De CandoUe's average standard of increase at diiFerent 

 periods of its gi-owth was correct, the author measured the trunks of 

 18 yews now standing in the churchyard of Gresford in North Wales, 

 which were planted out in 1726, and found their average diameter to 

 be 20 inches or 240 lines. By comparing these with the dimensions 

 of others whose ages are also known, he came to the conclusion that 

 for yews of moderate age, and where the circumference is less than six 

 feet, at least two lines or ^th of an inch of their diameter should be 

 allowed for annual increase, and even three lines or more if growing in 

 favourable situations. De Candolle says this tree increases little more 

 than one line in diameter annually during the first 150 years, and a little 

 less than one line afterwards, and in very old specimens he considers 

 their age to be at least equal to the number of lines in their diameter. 

 This average is too high for young yews, and, as will presently be seen, 

 too low for old ones. 



The author described a noble yew in Gresford churchyard whose 

 mean diameter is eight feet six inches or 1224 lines, and whose age, 

 by De CandoUe's method, would be as many years. Sections taken 

 from different sides of its trunk contained as follows : 



Average number of annual rings 'j On the north side. . 43 

 per inch counted on the hori- > On the south side. . 46 



zontal plane J On the S.W. side. . 15 



giving a general average of 34f rings in an inch of the diameter. As- 

 suming that this yew, when 120 years old, had a diameter equal to the 

 average of the 18 already mentioned, and among which it grows, and 

 that it continued to increase in the same ratio up to 150 years, and also 

 making additional allowance for an intermediate rate of increase between 

 150 and 250 years, we arrive at the following result : at 150 years old 

 its diameter would be 25 inches, at 246 years old 33 inches, leaving 

 five feet nine inches of the diameter for subsequent increase, the radius 

 of which, at 34 rings to the inch, would contain 1173 rings or years' 

 growth. To this add 246, and its present age will be 1419 years. 



A still greater yew in Darley churchyard, Derbyshire, having a mean 

 diameter of nine feet five inches, was next described. tSections taken 



