//A'.Y.SV y r AM* WWIFIC (SUAVITY

by the density of water at /°. Or it can be converted into specific,

/°
gravity at . 0 by multiplying by the ratio of the density of water

at /° to that at t\\ the latter symbol representing any desired
temperature.

It cannot be too strongly emphasised that both temperatures
represented in these symbols should always be expressed or
understood. Because of failure to do thin there is much confusion
in the records in scientific literature.

Baume System. In this system two scales arc; used, one
being for liquids lighter than wafer, the other for liquids heavier
than water. The first is applicable, to petroleum products and
to most other oils and fats. The; neeond Beale in used for most
solutions iu wafer.

In the original Baumc! scale, for liquids heavier than water
the point to which it hydrometer float sinks in a solution of
sodium chloride, 15 per cent by weight and at lf>**0'., wan taken
as 1-5° Bituiiti' (abbreviated Be!.). The corresponding point for
pun* water was taken as (f Be, and all other points were* located
by thene two. For liquids lighter than water the- scale has the
point 10n Be. for pure water and (f Be\ for a 10-per c«»nt, solution
of Hodimii rhlf*rif!i», tlifscnh* fii'ing extended beyond 10° for lighter
liquids. If will bt» 141*1*11 that this is u wholly arbitrary nywtcm
itfid cfrnversion of degrees Baiim/* into HjH»rific gravity^ or vice
versa, will involve ibi» u««* of s|M*ciul formuhin. Hevenil modifica-
tions of the original Baunie* walon have c<»nu» into uwt and I lie
(HfliciiltieH involved in interpmtHtion hav<t been <*orn*Hp<iiuliagly
increased. On account of the complexity <if t.he Hy«tem and the
fact that Htirli a synti'in wfitm f|tiiti» unn(^c«»HHary it in unfortunate
that it tiiw ttrt'onii* .HO gefieriilly tim*d in the chcinical indtiHtrieH,

No urie set of fiiriiiiilii}4 ran nerve for the conversion of sjM*cific
gravity and Biiiiiiii' fli'*gr«'i*i4, intt^ one another but an the HVtttrin
IH lit pn*Hi'iil u^ed in nmny imiustnal lubonttoric^H the following
forniiiliiH will l«* useful.

For liquids hc*avi«*r than water;

14 -r>

I

and

li

145