804  Scientific  and  Technical  Abstracts.     { Am^Z'mi.rm' 
Butter  fat  shows  a  seasonal,  variation  in  the  fat-soluble  vitamin  con- 
tent when  obtained  from  stall-fed  cows  during  the  winter  and  pas- 
tured in  the  summer.  The  fat-soluble  vitamin  content  of  butter  fat 
does  not  run  closely  parallel  to  the  yellow  pigment ;  yet,  in  general, 
due  to  determination  by*  their  content  in  the  feed,  butters  highly 
pigmented  are  rich  in  the  vitamin;  butters- ^low  in  pigment  should 
be  looked  upon  with  suspicion.  In  beef  fats  the  relations  are 
somewhat  similar;  those  most  pigmented  are  also  generally  richest 
in  their  fat-soluble  vitamin  content.  The  fat-soluble  vitamin  with- 
stands severe  methods  of  saponification.  This  indicates  that  it  is  not 
a  fat,  and  probably  not  an  ester. —  (H.  Steenbock,  M.  Sell  and 
M.  V.  Buell,  [Journ.  Biolog.  Chem.,  Baltimore,  June,  1921,  p. 
89;  through  Journ.  Amer.  Med.  Assoc.,  July  9,  1921,  p.  152.]  ) 
Insect  Powder  Dermatitis. — An  occupational  dermatitis  has 
been  found  to  occur  among  the  workers  engaged  in  the  manufac- 
ture of  pyrethrum  insect  powder.  Chemical  analyses  of  pyrethrum 
have  established  various  constituents  having  irritant  properties.  The 
lesions  noted  are,  essentially,  various  forms  of  dermatitis  venenata. 
They  are  of  mild  severity  and  quickly  disappear  under  ordinary 
treatment.  Re-exposure  frequently  leads  to  the  reoccurrence  of 
the  disease.  This  dermatitis  may  be  prevented  by  the  introduction 
of  trade  processes  that  eliminate  the  necessity  of  exposure  of  work- 
ers to  pyrethrum  dust  and  powder. —  (Through  Journ.  Amer.  Med. 
Assoc.) 
Effect  of  Cold  and  Freezing  on  Certain  Preparations. — 
E'we  has  studied  the  effect  of  freezing  upon  magnesium  magma  and 
finds  that  after  freezing  and  thawing  the  normal  water  content 
of  the  magnesium  hydroxide  gel  is  changed,  with  the  result  that 
molecules  of  magnesium  hydroxide  unite  to  form  a  fine  crystallized 
powder.  This  formation  is  practically  irreversible  and  cannot  be 
brought  back  to  the  collodial  state.  Other  pharmaceutical  prepara- 
tions are  likewise  affected  by  freezing;  Magma  of  bismuth  sub- 
carbonate,  elixirs  containing  terpinol  hydrate,  Fowler's  solution, 
compound  solution  of  sodium  phosphate,  compound  solution  of 
hypophosphites,  and  solution  of  hydriodic  acid,  solution  of  ferrous 
iodide,  and  solution  of  hydrogen  peroxide. —  {Amer.  Druggist.) 
