270 



Mr. A. M. Wortliington on the 



[June 15 J 



Set 3. 



Milk (boiled) on smoked glass. Diam, of drop 6-012 millims. Heiglit of fall 



100 milUms. 



I. Number of arms uncertain, 

 la. Vertical section of the same between the arms. 

 Hoc. & Ilia are phases of an alternative course, sometimes taken instead of II & III. 

 lY. This phase is consecutive on either III or Ilia. 

 V. The centre rises before the arms have come in. 



Set 4. 



llilk on smoked glass. Diam. of drop 6-012 millims. Height of fall 200 millims. 

 I. Very much spread out ; arms beaded, tending to split into rows of drops. 

 Ila is an alternative phase sometimes seen instead of II ; the centre having been 

 torn, the arms contract into the ring thus formed. 



Falling from a height of 280 millims. on a smoked glass plate, the same 

 sized drop of milk went through, phases similar to those of mercury from 

 150 millims. (see Set 8). 



The succeeding figures represent the forms assumed by a drop of mer- 

 cury 4-05 millims. in diameter falling on smoked (sometimes on imsmoked) 

 glass from the heights stated. 



The first height of fall was 34 millims. 



The phases in this case were verj- similar to those of milk falling from 

 50 millims. (Set 2), the main difi'erence being that the arms were not so 

 long and did not split ofi" into drops, while the centre was deeply hollowed 

 as in fig. IV. Set 2 ; after which the central part filled up and rose before 

 the arms came in, as in the case of milk. 



From a height of 60 millims. on imsmoked glass the consecutive phases 

 were very similar to those of 34 millims. fall. On smoked glass, however, 

 the arms were longer, and the resemblance to the forms seen in the case of 

 milk was closer than on unsmoked glass. 



An alternative course was often taken by the drop, of which the phases 

 are given on 



Set 5. 



I. The thickness of the central portion is very slight. 

 II. The thickness diminishes, till the central membrane of liquid tears in the centre 

 and flows to the circumference ; or more frequently the tearing takes 

 place tmder the edge of the oviter band, leaving such forms as III, IV, & V 

 where the white represents the mercury and the black the plate. After 

 this the succeeding stages were as in VI and 

 VU, where the arms contract into the ring, which splits into drops, as in VIII 

 These run together. The final stages are like those of milk. 



Set 6. 



Mercury on imsmoked glass. Height of fall 100 millim?. 

 I. Slight waves on the central patch. 

 II. This, when illuminated by reflection from a concave mirror at the side, looked 

 like two concentric circles of drops, showing probably that the raised cir- 

 cular band A A seen in the section Ila was lobed where the arms joined it 

 III. Sometimes the contour was almost circular, being very slightly lobed. 



If the plate was in the least dirty, irregular forms were seen, as in JTVa 

 IV/3, & Va ; otherwise the final stages were very similar to those of milk- 

 such deviations as V and VI being seen. 



