g6         Recent  Literature  Relating  to  Pharmacy.     { AFebr0uarryPi™' 
(3)  The  temperature  of  titration  should  not  exceed  that  of  the 
atmosphere. 
(4)  The  most  favorable  condition  of  solution  for  titration  with 
each  of  the  several  indicators  is  as  follows : 
Tincture  of  pernambuco-wood,  tincture  logwood,  haematoxylin, 
brasilin,  azolitmin,  tincture  litmus,  phenolphtalein  and  rosolic  acid 
with  water  alone,  chloroform  and  ether  to  be  particularly  avoided 
with  last  two ;  fluorescein  and  gallein  with  water  and  ethereal  layer 
containing  the  alkaloids ;  luteol  in  water  or  alcohol,  chloroform  and 
ether  being  avoided.  Tincture  of  curcuma  and  poirroir  blue  have 
been  suggested  as  indicators,  but  both  are  worthless.      H.  V.  A. 
ESTIMATION  OF  TOTAL  SOLIDS  IN  URINE. 
This  estimation  is  difficult,  for  evaporation,  even  on  water-bath, 
causes  decomposition  of  urea,  and  erroneous  results  in  conse- 
quence; and  evaporation  in  vacuo  is  convenient  only  to  expert 
chemists;  hence  calculations  based  on  the  density  of  the  urine  have 
been  employed,  the  best  known  being  the  method  of  Haeser,  who 
multiplies  the  two  figures  representing  hundredths  and  thousandths 
of  specific  gravity  by  a  constant  coefficient  2-33,  the  product  being 
grammes  of  solids  in  a  litre  of  urine.  Thus,  specific  gravity  1-020 
would  show:  20  x  2-33  equals  46-6  grammes  solids  to  litre. 
J.  Amann  {Schw.  WochscJi.  f.Cli.  und  Ph.,  1900,  p.  141),  on  study 
of  the  subject  with  an  artificial  urine  of  known  strength,  finds  that 
the  coefficient  is  not  constant ;  that  the  line  representing  relation  of 
density  is  not  straight,  but  a  hyperbola.  He  therefore  devised  a 
table  which  he  claims  is  reliable  ;  unfortunately,  however,  based  on 
amount  of  total  solids  of  invariable  composition,  viz.:  Urea,  60 
per  cent.;  salt,  36  per  cent.;  extractive  (sugar),  4  per  cent.  Were 
the  proportion  of  inverted  sugar  greater  than  that  above,  different 
results  might  be  obtained,  and  likewise  the  presence  of  albumen 
may  affect  result,  hence  extended  work  is  highly  desirable.  Amann's 
table  in  abbreviated  form  is  as  follows : 
Specific  gravity    .   roio    1*015    1-020    1-025    i'03o    1-035  1*040 
Total  solids,  grammes  in  litre  .  20-3     30'S     41-6     55-5      70*3     83-4  95*2 
Lastly  he  gives  an  equation  for  estimation  of  total  solids  in  urine  of 
any  specific  gravity,  namely,  total  solids  =  6-4  -f-  1-02  P  -f  0037P2; 
"  P  "  representing  difference  between  specific  gravity  of  the  urine 
and  that  of  water,  expressed  in  units.  H.  V.  A. 
