55° 
V arieties. 
{Am.  Jour.  Pharm-.. 
Nov.,  1878. 
On  the  upper  Amazon  and  in  the  province  Ceara  the  manner  of  collection  differs 
slightly  j  there  the  native  cleans  the  outer  bark  carefully,  and  having  surrounded  the 
tree^with  a  clay  spout  makes  a  large  number  of  incisions  above  this,  allowing  the 
juice  to  run  down  over  the  bark  into  the  spout,  which  accounts  for  the  impurities- 
always  found  in  that  caoutchouc,  known  as  Saramby. 
Cross  thinks  that  a  by  far  preferable  method  of  preparing  the  juice  would  be  to 
expel  the  water  by  heating  the  juice  in  shallow  dishes  over  a  water-bath,  and  also 
that  many  regions  of  the  Malayan  Peninsula,  of  British  Birma,  Ceylon  and  Coro- 
mandel  would  be  suitable  for  cultivating  Hevea  elastica. — L.  V.  C. —  Pharm.  Zeitschr* 
f.  Russl.y  July  1,  1878,  p.  407,  from  Oest.  Handelsjourn. 
Guaiacum  as  a  Test  for  Copper.  By  E.  Purgotti. — Schonbein  had  noticed' 
that  copper  salts  in  presence  of  cyanides  gave  a  blue  color  with  guaiacum,  and  the 
author  has  since  found  that  ferrocyanides,  nitroprussides,  sulphocyanates  and  cya- 
nates,  and  also  alkaline  chlorides  and  chlorides  of  the  alkaline  earths  produce  the 
same  effect  as  cyanides.  On  this  reaction  he  has  found  a  test  for  copper.  The 
solution  which  must  be  free  from  all  substances,  such  as  ferric  salts,  etc.,  which 
color  guaiacum  blue,  is  mixed  with  a  solution  of  an  alkaline  chloride  and  poured 
gently  down  the  side  of  a  test-tube  containing  an  alcoholic  solution  of  guaiacum ; 
if  the  most  minute  trace  of  copper  is  present  a  blue  color  is  produced  at  the  junction 
of  the  two  liquids,  and  if  the  quantity  of  copper  be  larger  the  whole  of  the  liquid 
becomes  blue  on  agitation  ;  in  this  way  'ooi  milligram  of  CuSO^H^O  in  a  decigram, 
of  water  gives  a  distinct  coloration.  The  action  appears  to  be  due  to  oxidation  by 
the  cupric  chloride  2CuCl2+H20  =  Cu2Cl2+2HClf  O.— Jour.  Chem.  Soc.  [Lon.],, 
September,  1878,  from  Gaxetta  chimica  italiana,  viii,  104 — 107. 
Estimation  of  Calcium  Tartrate  in  Crude  Tartars.  By  A.  Scheurer-Kestner. — 
The  ordinary  method  of  estimating  calcium  tartrate,  by  precipitating  a  solution  of 
the  crude  tartar  in  hydrochloric  acid  with  caustic  ^.oda,  does  not  give  correct  results 
in  presence  of  calcium  sulphate,  as  the  calcium  sulphate  and  sodium  tartrate  undergo, 
double  decomposition,  forming  calcium  tartrate  and  sodium  sulphate. 
To  avoid  this  source  of  error,  it  is  proposed  to  dissolve  the  tartar  in  hydrochloric 
acid,  and  to  precipitate  the  whole  of  the  tartaric  acid,  as  calcium  tartrate,  by  the 
addition  of  calcium  chloride  and  caustic  soda.  The  precipitate  is  washed,  dried, 
and  calcined,  and  the  resulting  calcium  carbonate  estimated  by  titration  in  the  usual, 
way. 
Another  portion  of  the  tartar  is  treated  with  hot  water,  and  the  solution  is  titrated 
with  standard  soda.  From  these  data  the  amount  of  calcium  tartrate  and  of  potassium, 
bitartrate  in  the  crude  material  can  be  calculated. — Ibid.,  August,  1878,  from  Compt , 
rend.,  lxxxvi,  1024 — 1025. 
