728 
Scientific  and  Technical  Abstracts 
Am.  Jour,  Pharm. 
Oct.,  1921. 
for  top-dressing  lawns  in  the  spring  do  not  develop  acidity,  and  per- 
mit the  coarsely  growing  weeds  to  crowd  out  the  grass.  Nitrogen  is 
commonly  furnished  in  nitrate  of  soda,  which  tends  towards  an  al- 
kaline reaction.  By  substituting  a  similar  amount  of  sulphate  of 
ammonia,  which  is  not  more  expensive,  an  acid  condition  of  the  soil 
is  gradually  produced  which  weakens  the  weeds,  while  not  affecting 
the  special  grasses  referred  to — bent  Grasses  or  Fescues.  Thus  in 
two  or  three  seasons  the  weeds  will  entirely  disappear,  or  in  new 
lawns  will  never  become  troublesome.  The  phosphorus  can  be  applied 
in  acid  phosphate,  and  the  potash  in  muriate  of  potash,  as  usual.  Dif- 
ferent soils  require  different  amounts  of  plant  food ;  but  a  good  pro- 
portion for  average  conditions  is  250  pounds  of  sulphate  of  am- 
monia, 400  pounds  of  acid  phosphate,  and  250  pounds  of  muriate  of 
potash  to  the  acre.  A  smaller  quantity  than  this  should  be  used  on 
newly-seeded  lawns.  A  too  heavy  application  of  sulphate  of  am- 
monia will  injure  the  grass  as  well  as  the  weeds ;  but  in  the  propor- 
tion noted  it  may  safely  be  used  as  freely  as  the  common  lawn  fer- 
tilizers. It  is  necessary  that  the  fertilizer  be  distributed  evenly  when 
the  lawn  is  dry,  in  order  not  to  burn  the  grass ;  and  where  conven- 
ient it  is  well  to  sprinkle  the  lawn  thoroughly  after  applying  the 
fertilizer. — Gas  Journal,  through  Chem.  Trade  lourn.,  July  30,  192 1, 
An  Ideal  Zinc  Ointment. — Mr.  A.  H.  Clark,  of  the  School  of 
Pharmacy,  University  of  Illinois,  read  a  paper  before  the  American 
Pharmaceutical  Association  on  the  best  formula  for  zinc  ointment 
from  the  standpoints  of  therapeutic  activity  and  keeping  qualities.  He 
found  that  an  ointment  made  with  lard  produces  a  disagreeable 
odor  and  becomes  granular.  With  lanoline  and  yellow  soft  paraffin 
an  unpleasant  odor  develops.  White  wax  gives  an  ointment  that 
is  very  liable  to  shrink.  The  ideal  ointment  is  obtained  with  the  fol- 
lowing formula: 
128. 
Soft  white  paraffin 
Hard  paraffin  
Zinc  oxide   
65  parts 
15  parts 
20  parts 
This  ointment  is  odorless,  does  not  shrink,  nor  does  it  separate 
or  granulate. 
