c ,. •'■ /?: 



Dr. A, Waller's Microscopic Observations on Hail. 105 



been altered by moisture or by caloric, I call on the same 

 principle amorphous snow. 



I will now proceed to mention the results of a few observa- 

 tions I have made upon hail. 



March 22, 1846. — There was a fall of hail which lasted 

 several minutes. The hailstones were generally of a lenti- 

 cular shape, about half the size of a French bean, of a dull 

 white colour, and semi-transparent. As they fell they were 

 received in a blanket on this and on the following occasions, 

 as when folded up in it, they might be preserved much longer 

 from melting. One of them placed under the microscope 

 was found to disengage bubbles of air in great abundance ; 

 its surface presented several irregular fissures by reflexion. 

 After liquefaction, the drop of water resulting was found to 

 contain numerous particles of various forms. Some of these 

 were perfectly spherical, transparent, and agglomerated toge- 

 ther in groups. Some were single, with a central nucleus, 



Fig. 1. 



o 



<p 



o 



others were completely opake, black, and globular. Other 

 hailstones contained, besides particles similar to the above-de- 

 scribed, some of a siliceous appearance, causing a gritty feel 

 when compressed between surfaces of glass. Shortly after 

 the hail there followed a fall of rain : some drops of it being 

 examined in the same way, were found to contain numerous 

 irregular particles, some of which were apparently particles 

 of soot, but I could detect no globular particles, nor an} T re- 

 sembling sand. 



March 23. — There occurred a fall of hail more considerable 

 than the former, but the hailstones were smaller, though of 

 similar shape. At the commencement of the fall, the hailstones, 

 as soon as they struck the earth, split into numerous fragments, 

 which remained loosely adhering together, much like wet sand 



