428         ACTION  OF  BOILING  LIQUIDS  UPON  GLASS,  ETC. 
odor,  resembling  coumarin  ;  it  has  the  character  of  an  aldehyde, 
and  yields  with  sodium  amalgam,  among  other  products  two  crys- 
talUzable  alcohols. 
The  authors  have  also  studied  the  effect  of  bromine  upon  the 
acid  and  by  oxidizing  piperonal  with  permanganate  of  potassa, 
a  new  acid,  piperonylic  acid  =  CJifi^  was  obtained. 
The  experiments  are  insuflScient  to  determine  the  constitution 
of  piperinic  Sicid.—Zeitschr.  f.  Chemie,  1869,  826-332. 
ACTION  OF  BOILING  LIQUIDS  CONTAINING  ACIDS  AND 
ALKALIES  UPON  GLASS  AND  PORCELAIN  VESSELS. 
By  Dr.  A.  Emmerling. 
This  essay,  or  rather  monograph,  contains  the  record  of  a  se- 
ries of  most  minutely  executed  experiments,  whereby  to  deter- 
mine the  influence  of  various  fluids,  containing  acids,  salts,  and 
alkalies,  upon  vessels  made  of  different  qualities  of  glass  and  por- 
celain, in  order  to  determine  the  amount  of  substance  dissolved 
by  such  chemicals,  and  also  by  pure  distilled  water,  and  to  as- 
certain what  influence  is  thus  exercised  upon  the  accuracy  of 
analysis  and  chemical  researches  in  general.  This  monograph 
is  full  of  interesting  details,  including  analyses  of  glass.  Un 
resume,  its  leading  features  are  the  following :  The  action  of 
boiling  liquids,  as  specified  above,  upon  glass  vessels  is  propor- 
tionate to  the  duration  of  time  of  boiling ;  the  action  is  propor- 
tionate to  the  surface  which  is  in  contact  with  the  boiling  fluid ; 
the  action  is  independent  of  the  quantity  of  fluid  which  evapo- 
rates during  a  given  time  ;  the  action  decreases  with  the  decrease 
of  temperature  of  the  solution  ;  alkalies,  even  in  dilute  solutions, 
attack  glass  very  strongly ;  acids  generally  act  less  than  pure 
water,  excepting  sulphuric  acid  ;  among  the  salts,  those  act  most 
energetically  whose  acids  produce  insoluble  salts  with  lime — e.  g., 
sulphate  and  phosphate  of  soda,  carbonate  of  soda,  and  oxalate 
of  ammonia,  the  action  of  each  of  which  increases  with  the  degree 
of  concentration  of  the  solution  ;  such  salts  as  form,  in  water, 
readily  soluble  lime  salts — for  instance,  the  chlorides  of  ammo- 
nium, potassium,  calcium,  and  nitrate  of  potassa — less  strongly 
than  pure  water  alone,  and,  with  the  greater  degree  of  concen- 
