FEB. 1g01. OBSERVATIONS ON INDIANA CAVES—FARRINGTON. 251 
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 

Fic. 2—Stalactite, Marengo Cave, 
is to be supposed that the capillary showing form probably influenced 
F ats by capillary deposit. 
currents producing such deposition ¥% nat. size. (Mus. No, G. 963.) 
*Abstract in Am. Jour. Sci., Vol. 160, p. 392. 
* 
