170  Selections  from  the  Danish  Journals.  {AmA^n,ri87h7arH1' 
was  480,  but  many  of  them  were  weighed  every  day  for  the  first  four- 
teen days. — Ibid.,  1876,  p.  483,  from  Zilr.  Gesundheitspflege,  1875. 
Gold. — Jul.  Thomsen  (well-known  for  his  thermo-chemical  re- 
searches) has  examined  into  the  behavior  of  gold  and  its  salts,  and  found- 
that  there  exist  three  allotropic  states  of  it  :  1.  Gold  reduced  from 
a  solution  of  the  chloride  by  sulphurous  acid,  forms  a  lumpy  mass.  2. 
Reduced  from  the  bromide  it  forms  a  very  fine  dark  powder,  which 
keeps  its  powdery  form  even  after  drying.  3.  If  reduced  from  proto- 
chloride,  bromide  or  iodide,  it  forms  a  very  fine  powder,  with  yellow 
color  and  metallic  lustre.  Mr.  Th.  has  prepared  and  reports  at  great 
length  on  Au2Cl4,  AuCl3,  AuCl,  AuBr3+AuBr,  AuBr3, 
AuBr4H+5H20,  AuBr,  Au203.— Ibid.,  1877,  p.  1,  from  TidsL 
Phys.  and  Ch. 
Hardened  (toughened)  Glass. — There  exists  a  factory  in  Pitts- 
burgh, Pa.  (Ditheridge  &  Co.,  Fort  Pitt  Glass  Works),  which  makes 
that  kind  of  glass  after  a  secret  process  of  its  own.  La  Bastie's  pro- 
cess consists  in  a  peculiar  way  of  hardening.  The  above-named 
American  firm  obtained  the  above  results  by  a  peculiar  composition  of 
the  glass  mass.  The  editor  thinks  it  probable  that,  considering  the 
great  hardness  and  peculiar  transparency  and  freedom  from  color,  borax 
seems  to  play  a  role,  and  is  probably  the  real  secret. — Ibid.,  1876,  p.  476. 
Antichlor. — Hitherto  only  hyposulphite  of  sodium  has  been  used  as 
antichlor  ;  but,  notwithstanding  its  great  absorption  power  for  chlo- 
rine, it  has  one  drawback — sulphur  is  precipitated,  which  is  soon  oxi- 
dized to  sulphuric  acid,  and  "  rottens  "  the  paper  or  tissues.  Although 
sulphite  of  sodium  is  not  decomposed  in  this  way,  its  absorption  power 
for  chlorine  is  very  weak,  and  therefore  it  could  not  replace  the  hypo- 
sulphite. R.  Wagner  recommends  nitrite  of  sodium,  which  does  not 
in  any  way  attack  the  bleached  articles.  The  relative  absorption  pow- 
ers of  these  three  salts  are  as  follows  :  100  pts.  hyposulphite  take  hold' 
of  114*4  Pts-  chlorine;  100  pts.  sulphite  only  of  28*1  pts.  chlorine; 
100  pts.  nitrite  as  much  as  103  pts.  chlorine. — Ibid.,  1876,  p.  477. 
Dry  Rot. — The  best  preservative  against  dry  rot  is  the  following 
of  Mr.  Schwartze,  who  made  millions  by  it,  and  by  whose  recent 
death  the  secret  was  revealed  :  1  part  oil  of  cassia,  1  part  woodtar  and 
1  part  common  train  oil ;  apply  three  coats  on  the  reverse  sides  and  on 
the  ends  of  planks,  floors,  etc.  In  all  probability  oil  of  cassia  played 
the  chief  role  as  preservative. — Ibid.,  482. 
