30 Me. J. BracE on the Low Tennm-atures 



by either of the distinguished physicists above mentioned, would be a 

 great boon to the scientific worki. 



The influence of this severe season on trees and shrubs is remarkable. 

 The following particulars have been kindly furnished by Professor 

 Dickie of Queen's College, Belfast, being extracted from a paper by him 

 on the subject, now passing through the press : — 



In inland situations in Aberdeenshire, where there was a considerable 

 covering of snow in February, all the young plants of araiu:aria inibri- 

 cata were uninjured, except such as had branches protruding above the 

 snow. Near the coast line, the effects on whin and broom were most 

 conspicuous, for two reasons — the plants attain large size, and the cover- 

 ing of snow is less. Bushy plants, browsed by cattle, were uninjured, 

 owing to the covering of snow. The effects were more conspicuous on 

 these than on any other wild plants. They were generally killed in ex- 

 posed places nearly to the ground. In the summer, new shoots were 

 pushed out from below. Species of rosa, rubus, and salix, gi-owing along 

 with them, were uninjured. Sections of stems of whin and broom killed 

 by the frost were examined under the microscope, but no change in the 

 tissues could be detected. The only difference between them and sec- 

 tions of living ones was the existence of brown stains near the ducts ; 

 but this difference was not constant. There seems no way of account- 

 ing for the different effect of the frost, but by some original difference 

 in constitution among plants. A great many exotic trees, and shrubs, 

 were either materially injured or totally destroyed ; but it would 

 be rash to say that this indicates their inability to resist low tempera- 

 tures under any circumstances. In every instance it was observed that 

 the destruction was greater in low than in high situations, and this 

 even in the same garden. This was seen in places not more than 100 

 yards apart, and differing only twenty feet in elevation. Dr. Dickie, 

 rightly, we think, attributes this to accumulation of the heavier, colder, 

 and damper air in such localities. After giving many striking examples 

 from Aberdeenshire, the following is recorded from Belfast. The loss 

 there was less, partly because the minimum temperatm-e was greater 

 than in Aberdeenshire, exceeding it by 14° to 17° F., and partly from 

 the site of the garden being high and well drained. Among twenty 

 plants destroyed, there were nine species of the pine tribe, one heath, 

 and two other shrubs, which, in a locality three miles north-east, one 

 mile from the sea, and 450 feet above its level, stood wholly uninjured. 

 The Belfast garden varies from 50 to 75 feet above mean tide level. 

 Dr. Dickie gives full details in this important paper regarding the plants 

 destroyed in Aberdeenshire and at Belfast ; and calls attention to the 

 great value of observations and records on this subject, as affecting the 



