102 On Crystallization. [Ave. 
same results. I have kept some vessels thus exposed to the full 
atmospheric pressure for three days, without any consolidation; and 
others, during all the intermediate periods, with similar results. 
Sometimes one or more will crystallize, whilst others continue fluid. 
have made these experiments in phials holding from two drachms 
to 16 ounces; in receivers of a globular and oval shape, from half 
a pint to half a gallon; some with short, and others with long. 
necks; and in open glass jars of one to two inches diameter, and 
eight or nine long ; so that the form of the vessel in no way appears 
to influence the result.’ Nor has the quantity of solution in the 
vessel any influence, since it is the same when filled to the top, or 
when only filled to one-fourth or one-fifth part. The result was the 
same when | employed the common Glauber’s salts of the shops, 
the nafive, or the artificial, made by the direct combination of the 
constituents. In one experiment made with the artificial sulphate 
I filled three equal phials, two were closely corked, the third re~ 
mained open, and all were placed beside each other to cool. In 
four hours one of the corked solutions was regularly crystallized in 
solid transparent crystals, one-fifth only of the mass being in a liquid 
‘state, which did not consolidate by shaking, or by withdrawing the 
cork. ‘The contents of the other corked, and of the uncorked phial, 
both continued fluid; and loth became solid by shaking, without 
withdrawing the cork of the closed one. 
4. Solutions as above, after remaining exposed, have even not 
erystallized when briskly shaken, and some time afterwards without 
any apparent cause, have assumed the solid form. 
5. Solutions as above, and closely secured, have failed to become 
solid, when the cork has been drawn, or the bladder punctured, for 
some moments, and even minutes; and in a few cases when even 
agitation was employed in addition: and these, in like manner, 
when least expected, have suddenly crystallized. 
6. Solutions as above, both corked and uncorked, have gradually 
‘deposited regular transparent firm crystals,* in some instances two 
inches in length ; in others, in irregular masses, at the bottom of 
the vessel—the fluid above, in these cases, continuing clear and 
‘saturated ; and when shaken, sometimes consolidating in the usual 
way. 
7. Solutions as above, both corked and uncorked, after thus depo- 
siting these regular crystals at the bottom, have, without an appa- 
rent cause, become consolidated above them, whilst remaining 
untouched. 
8. Solutions as above (especially in a mattrass with a neck nearly 
two feet long), have, after considerable exposure and frequent agita- 
tion, refused to crystallize, even although continued at intervals for 
* The crystals which form suddenly in these solutions are always of a soft, 
spongy, silk, striated, appearance; and do not exhibit the firm, transparent, 
glassy, appearance of the common crystals of Glauber’s salt, 
oo 
