3O2 In and Around the Morteratsch Glacier : 



water has been frozen, there will remain only a cicatrix or 

 scar which will contain the microscopic liquid nucleus con- 

 sisting of brine of low freezing-point. In the glass-blower's 

 art we meet with scars of this class frequently. When two 

 pieces of glass tube are joined together before the blowpipe, 

 the joint is almost always characterised by a linear scar 

 which, when examined under the microscope, is found to 

 consist of a string of minute spheroidal discontinuities or 

 air-bells. Tn the course of my work the most perfectly healed 

 ice, or that in which the scar was least visible, was met with 

 in the Morteratsch grotto in February 1894 ; but there, as we 

 have already seen, the freezing and cicatrisation probably 

 took place in the dark. 



The features in winter are well shown in Figs. 10 and 11, 

 which were photographed on 5th March 1910, while the winter 

 still lasted. The ice-wall shown in Fig. 1 1 lies inside of that 

 shown in Fig. 10, which it slightly overlaps. White ice in its 

 interior is therefore less abundant than in the ice represented 

 in Fig. 10, which is close to the entrance of the grotto. The 

 forms assumed by the white ice in Fig. 10 are remarkable and 

 unusual. As it was near the end of winter, the ice-walls 

 shown in these illustrations were frozen to a depth of several 

 decimetres. 



It is the custom for the proprietors of glacier grottos to 

 have them repaired and enlarged every spring, so soon as the 

 frost has come out of the ice. In the innermost part of the 

 grotto, where the addition is always made, this happens very 

 quickly, partly because the winter cold of the outside is much 

 attenuated before it reaches the inner terminal chamber of 

 the grotto, and partly because lights of one kind or another 

 are maintained there for the benefit of sightseers, and this 

 interferes with the cooling of the ice. 



At the beginning of June 1910 I visited the new gallery 

 which had been driven in the spring in ice which is far 

 removed from external radiation, whether arriving by way of 

 the galleries of the grotto or by transmission through the 

 thickness of the ice above. I found the ice in general very 

 free from air-bells. Only where the miner had struck the ice 



