Feb. 1901. Observations on Indiana Caves — Farrington. 25r 



not say, while further it may be noted that Foote's* experiments led 

 him to conclude that rapidity of crystallization causes the formation 

 of aragonite rather than the slow crystallization which Senft has 

 postulated. 



Deposits Produced by Capillary Attraction. — The force of capil- 

 lary attraction cited by Merrill as producing the vermiform stalac- 

 tites is probably instrumental in modifying the forms of stalactites in 

 general in a way to which attention does not seem to have been 

 called before. In fact, it is probable that deposition from this cause 

 takes place on a much larger scale than has hitherto been supposed. 

 The nature of such deposits can be instructively determined experi- 

 mentally. As deposition of carbonate of lime from solutions would 

 take place too slowly for convenient study, I have used solutions of 

 salt for this purpose. 



Fig. 1 shows a deposit of salt formed 

 by capillary attraction on a slender 

 stalactite, a glass rod and a glass tube 

 respectively. These deposits were ob- 

 tained by supporting the several objects 

 on end in a solution of salt to a depth of 

 about one-fourth of an inch (6 mm.) for 

 a week. The deposit on the stalactite, 

 it will be noted, gathered about numer- 

 ous centers giving a stippled appear- 

 ance like that often seen on stalactites 

 and illustrated by the figure of the stalac- 

 tite shown in Fig. 2. This is in accord- 

 ance with the well-known tendency of 

 crystals to form secondary and tertiary 

 branches. It is to be noted so far as the 

 deposit on the glass tube is concerned 

 that none formed inside the tube. 

 Hence the stopping up of stalactite 

 tubes cannot be ascribed to this cause. 

 Attention may also be called to the large 

 amount of deposit both on the tube and 

 the rod, as indicating how considera- 

 ble a deposit on stalactites may result 

 from capillary attraction. In Nature it 

 is to be supposed that the capillary 

 currents producing such deposition 



Fig. 2— Stalactite. 



Marengo Cave. 

 showine form probably influenced 

 by capillary deposit. 

 % nat. size. (Mus. No. G. 963.) 



♦Abstract in Am. Jour. Sci., Vol. 160. p. 392. 



