604 
solution  of  lactic  acid  will  do  this  work  as  well,  and  is  much  easier 
to  control  in  its  action.  The  slightly  higher  cost  is  more  than  com- 
pensated for  by  the  prevention  of  waste.  To  the  researches  of  Mr. 
Wood  and  Mr.  Andreasch  (F.  Andreasch,  Der  Gerber,  21,  506;  22, 
513)  this  application  is  attributable.  In  America  over  300,000 
pounds  of  lactic  acid  have  been  consumed,  mainly  by  a  few  tanneries, 
during  the  last  six  months. 
In  the  household  lactic  acid  is  used  medicinally,  and  it  is  a  substi- 
tute for  other  acids  and  fruit  juices  in  making  acid  beverages.  The 
large  possible  application  of  lactic  acid  for  domestic  use — the  re- 
placing of  cream  of  tartar  by  the  acid  lactate  of  calcium — has  not 
yet  been  put  in  practical  operation. 
With  regard  to  the  analysis  of  lactic  acid,  I  feel  I  can  add  little 
to  what  Allen  has  collected  in  the  latest  volume  of  his  Organic 
Analysis  (A.  H.  Allen,  Commercial  Organic  Analysis,  Vol.  Ill,  Part 
III,  411,  et  seq.).  On  account  of  the  solubility  of  all  its  salts,  the 
direct  determination  of  lactic  acid  is  a  long  and  delicate  process. 
Generally  the  indirect  method — determining  total  acidity  and  per- 
centage of  foreign  acids — gives  more  expeditious  results.  There  is 
not  much  sophistication  of  lactic  acid.  Sometimes  acetic  and  mine- 
ral acids  are  found  in  it,  and  now  and  then  samples  of  so-called 
lactic  acid  containing  no  lactic  acid  at  all.  Usually,  however,  com- 
mercial lactic  acid  is  pure,  except  from  products  incident  to  manu- 
facture and  not  deleterious  in  effect.  The  strength  varies  from  20 
to  50  per  cent.,  according  to  the  price  and  for  what  purpose  the  acid 
is  intended  to  be  used.  - 
u  ON  A  SOLUBLE  COMPOUND  OF  HYDRASTINE  WITH 
The  following  experiments  were  made  in  connection  with  an 
endeavor  to  enlarge  the  number  of  soluble  salts  of  hydrastine, 
especial  interest  attaching  to  the  combination  of  the  alkaloid  with  a 
mineral  salt  of  recognized  value  in  medicine. 
MONOCALCIUM  PHOSPHATE.1 
By  T.  H.  Norton  and  H.  B.  Newman. 
1  Journal  of  the  American  Chemical  Society,  October,  1897. 
