BY MOLECULAR COALESCENCE. Vi 
as the secreting cell deprived of its calcareous element. 
These calculi can be made by mixing with one portion of 
white of egg a very small quantity of muriate of lime, 
and with another portion of the same a little sub-car- 
bonate of potash or soda, and then putting them together, 
without mixing them, into a bottle, into which two glass 
slides had been previously introduced, as in the process 
with the gum, and then keeping the bottle at rest for 
two or three weeks. This experiment must be made in 
cold weather, as the albumen rapidly decomposes. In 
examining these calculi for the purpose of seemg the 
albuminous residue, corresponding to the “ animal basis ” 
before mentioned, they should be examined on a micro- 
scopic slide, with a piece of thin glass over them at the 
time the acid is in action, which ought to be very weak, 
so that in the partially decalcified globules the perfect 
parts and the decalcified ones may be seen at the same 
time, and compared one with the other. The polariscope 
will be necessary in this examination. After all the cal- 
careous matter has been removed, the residue will be seen 
to be of the same size and with the same appearance of 
lamination as the original globule ; but these will of course 
be fainter and invisible under perfectly polarized light, 
showing that during the formation of calculi of this kind 
the albumen becomes solidified and molecularly blended 
with the carbonate of lime. This fact proves also, so far 
as it goes, that soft matter is as much under the influence 
of physical agency as hard matter, provided only the me- 
chanical conditions under which both are placed when 
acted upon are the same. I may observe, in concluding 
the remarks upon these calcul, that my conviction of the 
correctness and truth of the explanation here given of 
their origm and mode of formation, as opposed to the 
