472 
V arieties. 
("Am.  Jour.  Pharm- 
1     Oct.,  1875. 
because  it  quickly  destroys  the  contagion.  (4,)  In  all  cases  where  fermentative 
changes  occur  in  the  contents  of  the  alimentary  canal,  salicylic  acid  acts  more  effica- 
ciously than  other  antiseptic  substances,  since  it  can  be  administered  in  larger  doses. 
(5).  Its  use  is  highly  promising  as  a  prophylactic  in  all  diseases  in  which  it  is  believed 
that  the  morbid  processes  are  connected  with  microscopic  organisms.  In  diphtheria 
not  only  is  salicylic  acid  a  powerful  restorative  remedy,  but  it  also  appears  to  shorten 
the  course  of  the  disease. — Journ.  Chem.  Soc.  [Lond.],  Aug.,  1875,  from  J.pr.  Chem. 
[2],  xi,  57-63. 
Amylogen,  or  Soluble  Starch.  By  L.  Bondonneau. — Amylogen,  whether 
prepared  by  dilute  acids  or  alkalies,  or  by  water  underpressure,  always  possesses  the 
same  chemical  properties  by  desiccation.  It  becomes  translucid  with  conchoidal 
fracture  and  completely  insoluble  in  both  cold  and  boiling  water  5  but  when  mechan- 
ically divided  with  a  fine  file,  it  is  largely  dissolved  by  water  5  it  is  always  soluble, 
more  or  less  rapidly  according  to  its  state  of  cohesion,  in  soda  and  zinc  chloride. 
The  effect  of  cohesion  may  be  clearly  seen  in  amylogen  prepared  with  soda.  If 
carefully  precipitated  by  alcohol,  it  is  soluble  in  a  small  quantity  of  water  5  but  if  the 
precipitate  be  simply  compressed  between  the  fingers,  it  becomes  almost  insoluble. 
Amylogen  is  so  perfect  a  colloid,  that  it  may  be  considered  as  a  type. 
The  starch  granule  is  made  up  of  concentric  layers  separated  from  each  other  by 
a  cellular  membrane.  When  this  membrane  is  broken  up  by  soda,  &c.,  the  starch 
coming  in  direct  contact  with  water,  dissolves  therein. — Journ.  Chem.  Soc.  [Lond.]^ 
July,  1875,  from  Comp.  rend.,  Ixxx,  671. 
On  the  so-called  Chlorine  Hydrate.  By  C.  Gupner. — Chlorine  hydrate^ 
Clj-fio  H^O,  may  also  be  regarded  as  HOCl  +  HCl  -|-  9H2O.  If  the  first  of  these 
formulae  were  the  true  one,  the  substance  would  give,  on  treatment  with  mercury, 
only  mercurous  chloride  5  but,  as  a  matter  of  fact,  it  gives  chiefly  mercuric  chloride. 
A  small  amount  of  the  mercuric  chloride  is  reduced  by  the  excess  of  mercury  to 
mercurous  chloride.  The  molecular  arrangement  of  the  hypochlorous  and  hydro- 
chloric acids  might  possibly  be  arrived  at  by  treating  the  chlorine  hydrate  with 
organic  bodies.  Chlorine  at  0°,  therefore,  decomposes  water  in  the  same  way  as 
the  alkaline  hydrates  :- - 
CI2  4-  HOH      HCl  4  HOCl 
CI2  -f  K,0  +  H^O  =  KCl  +  KOCl  4  H.p. 
— Jour.  Chem.  Soc,  Aug.  1875,  ft"'-""^  Deut.  Chem.  Ges.  Ber.,  viii  287. 
On  the  Constitution  of  Chlorine  Hydrate.  By  Hugo  Schifl'. — The  the- 
ory that  chlorine  hydrate,  (Cl.^HO  +  icH^O),  may  be  represented  by  CIHO  4  HCl 
4-  9H.2O,  having  been  wrongfully  attributed  to  the  author,  he  denies  having  origi- 
nated it,  and  then  proceeds  to  give  an  historical  sketch  of  the  theory.  Afterwards 
he  brings  forward  facts  to  prove  that  in  all  probability  chlorine  is  not  present  as 
hypochlorous  acid  j  a  concentrated  hypochlorous  acid  solution  is  quickly  decomposed 
by  diffused  light,  whereas  the  hydrate  which  contains  nearly  the  same  amount  of 
chlorine  remains  unaltered.  The  hydrate  does  not  discolor  the  epidermis,  which  it 
should  do  if  hypochlorous  acid  were  present.     Neither  HCIO  nor  HCl  alone  forms 
