and on the Organic Bodies contaitied in Hailstones, ^r. 163 



tact with other bodies moisten them like common rain. This 

 may be regarded as simihir to the formation of rain in clouds, 

 except that it is on a much smaller scale, as the thickness of 

 the stratum of the iog is much less than the strata of clouds, 

 as measured by M. Peytier. 



We may examine the minute particles of rain or fogs, as I 

 have already shown, by passing the air which contains them 

 through essence ot" turpentine, lowered a few degrees below 

 the common temperature. They are then left behind in the 

 liquid ; but at the same time they are mixed with others which 

 arose from the condensation of the water contained in the air 

 in an elastic condition. Difficulties exist with regard to the 

 measurement of the globules while floating about. This is an 

 objection to the employment of this method of fixing the glo- 

 bules. I have therefore endeavoured to use another means 

 of observing these particles, and for this purpose have ex- 

 amined them as they exist on the filaments which compose the 

 spider's web. 



In order to examine these globules m siiti, it will be found 

 convenient to make use of two square frames of sheet cork of 

 equal size, about two or three inches square. These are to 

 be placed on each side of the web, then pressed together and 

 bound. The whole of the web interposed may then be re- 

 moved with the globules in statu quo, which may then be sub- 

 mitted to the microscope and measured. The globules may 

 sometimes be as small as yjotj'-^^ ^^ ^" inch, which is less than 

 the globules of the clouds in some instances as measured by 

 Kaemtz. But generally these globules are much larger. 

 They will be found placed at regular intervals, and while 

 undisturbed show little tendency to coalesce; but when taken 

 into a warm room they appear to lose with the increase 

 of temperature, their cohesion to the line, and easily run 

 off, coalesce with each other and rapidly evaporate; while so 

 doing, instead of a globular form they become elongated ellip- 

 soids, with the long diameter in the direction of the spider's 

 line running through tiiem. In the same fog I have found 

 these globules always of the same dimensions. When the 

 webs are examined over the extent of one or two miles at least, 

 but in different logs, their sizes are very different. It is ne- 

 cessary to warn the observer respecting an error that might 

 be easil)' made in examining the web of the common spider, 

 because in its natural state it is found covered with minute 

 globules or beads, which contribute probably to secure the 

 prey of the animal. These beads are arranged with great 

 symmetry. Thus at nearly equal distances will be ibund 

 globules, as in fig. 2, and between them others smaller dis- 



