Mr. Henry cn the Prefervatkn, &c. 41 
owing to the proportion of filver contained in 
the ores. 
Some writers affirm, that native gold has been 
found in a cryftallized ftate, and the form it 
aflumes is that of a prifm of eight fides. 
With thefe obfervations I ffiall conclude this 
paper, which has been extended to an unreafon- 
able length, for which, I hope, the importance 
of the fubjed will plead my excufe. 
On the Preservation of Sea Water from 
Putrefaction by Means of Quicklime. By 
Thomas Henry, F. R. S. to which is added , an 
Account of a newly invented Machine for impreg¬ 
nating Water or other Fluids with Fixed 
Air, &c. communicated to Mr. Henry by 
I. Haygarth, M. B. F. R. S. Read Novenu 
ber 21, 1781. 
I T has been frequently repnarked by chemical 
and philofophical writers, that a new experi¬ 
ment is feldom made in vain. Though the ope¬ 
rator may even fail of attaining the immediate 
obje.Ct of his purfuit, he may yet, fortuitoufly, 
acquire the knowledge of fome new fad, which 
may be productive of improvemant and advan¬ 
tage to fcience. 
About 
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