64 
Book  Reviews. 
Am.  Jour.  Pharm. 
January,  1920. 
the  determination  of  the  facts  recorded  therein  represents,  on  the 
part  of  the  original  workers  or  investigators;  nor  can  he  help  being- 
impressed  with  the  vast  amount  of  painstaking  labor  that  must  have 
been  done  by  the  author  of  the  present  volume  in  its  compilation. 
In  the  preface  the  author  says:  "The  principal  object  in  preparing 
a  compilation  of  solubility  data,  from  the  point  of  view  of  the  ad- 
vancement of  chemistry,  is  to  furnish  material  for  the  origination 
and  verification  of  theories  of  solution,"  but  one  can  readily  see  how 
this  volume  may  be  of  great  value  to  anyone  whose  work  has  to  da 
with  the  solubility  of  substances  in  various  solvents  and  under  vary- 
ing conditions.  F.  P.  Stroup. 
AnnaIvS  of  the  Missouri  BotanicaIv  Garden,  Vol.  6,  No.  3,  Sept., 
1919. 
An  Edible  Garden  Hebeloma. — B.  A.  Burt  describes  and 
pictures  an  edible  Heheloma,  which  he  found  in  great  abundance  in 
cultivated  borders  of  the  Missouri  Botanical  Garden  on  June  3rd, 
and  which  he  names  H.  hor tense. 
This  species  differs  from  the  majority  of  other  members  of  the 
genus  Heheloma  in  that  its  fructifications  are  devoid  of  viscidity^ 
and  odor  of  radishes  and  its  occurrence  in  abundance  in  cultivated 
ground.  Nearly  all  the  other  species  of  Heheloma  are  found  spar- 
ingly in  forests  and  are  either  inedible  or  poisonous. 
ProtomeruIvIUS  FarIvOwii. — The  same  author  describes  and 
pictures  another  fungus  which  was  collected  by  Dr.  Farlow  at 
Chocorua,  New  Hampshire.  This  he  named  ''Protomerulius  Far- 
lowii.''  Its  fructifications  occur  on  rotten,  decorticated,  coniferous 
wood  in  small  gregarious  patches,  eac§*  being  gelatinous,  membra- 
nous, very  thin  and  tender,  purple  when  fresh,  becoming  pale 
olive-gray  on  drying,  showing  under  the  microscope  an  imperfectly 
porose  surface  with  thin,  irregular  folds  and  more  or  less  lacerated 
dissepiments. 
The  Micro-Calorimeter  in  the  Indicator  Method  of  Hy- 
drogen Ion  Determination. — B.  M.  Daggar  finds  that  the  Du- 
boscq  type  of  micro-colorimeter  lends  itself  admirably  to  determining 
the  H  ion  concentration  in  small  quantities  of  fluids.  The  procedure 
is  briefly  described  and  the  method  of  standardizing  the  apparatus, 
carefully  explained. 
