and on the Organic Bodies contained in Hailstones^ S^-c. 167 



snow may continue until all traces of separate crystalline par- 

 ticles have disappeared and the air has been disengaged, the 

 whole becomes transparent, and still capable, by its low tem- 

 perature, of easily solidifying and forming a transparent mass 

 of ice. In either case the deposition of successive layers of 

 transparent ice, or of confused solid grains, may be accounted 

 for by a continuance of the same actions. 



In order to exemplify this, it is not requisite to confine our- 

 selves merely to snow already in a globular state : any kind of 

 snow slightly pressed into a globular shape becomes hardened 

 and modified by diffusion of water through it, inconsequence 

 of slight melting of its particles. According as this is more or 

 less continued, we obtain all the dull white tints of various 

 hailstones. If the mass thus obtained be now exposed to the 

 air below the freezing-point, the process is still iurther com- 

 pleted by its entire solidification. 



It still remained to be seen whether the conglomerations of 

 snow contained, like hail, any organic particles. I was desi- 

 rous to determine this point, because I considered them as 

 being much less liable to contain foreign matter, such as dust 

 &c. of the lower strata of air, than the common flakes of snow: 

 at the same time we must admit the possibility of the intro- 

 duction of foreign particles, even after the entire formation of 

 the ball, much more than in a solid body of ice like a hail- 

 stone. 



In order to obtain a ball as free from impurity as possible, 

 one of the hardest was selected, and after the exterior parts 

 had been carefully brushed off, it was inclosed in the little 

 apparatus before described. Several conglomerations were 

 operated upon in this manner. In these the foreign particles 

 were numerous; they all appeared irregular and of an amor- 

 phous inorganic nature, except some green globules closely 

 agglomerated together, some in large quantities, others only 

 consisting of groups of three or four : their size was about 

 n^-jj^jjjth of an inch, and they were very similar to some found 

 in hail, the vegetation of which was not examined (see p. 105, 

 vol. xxviii. Phil. Mag.). The drops of water resulting, with 

 their contents, were examined every day. The first two 

 days they were kept in a room which averaged a few de- 

 grees above congelation ; no alteration of the particles was de- 

 tected. The third day they were exposed to the rays of the 

 sun: on the fourth day the green globules had emitted slight 

 filaments. Every succeeding day these filaments increased, 

 and near them were transparent granules scattered about 

 which increased very slowly, as represented at fig. 3. These 

 vegetations were preserved lor more than a month by occasion- 



