﻿Chemistry 
  and 
  Physics. 
  381 
  

  

  SCIENTIFIC 
  INTELLIGENCE. 
  

  

  I. 
  Chemistry 
  and 
  Physics. 
  

  

  1. 
  Note 
  on 
  the 
  Preparation 
  of 
  Glycerine 
  by 
  Fermentation. 
  — 
  

   Karl 
  Schweizer 
  has 
  explained 
  his 
  experiments 
  which 
  led 
  to 
  a 
  

   greatly 
  increased 
  yield 
  of 
  glycerine 
  during 
  the 
  fermentation 
  of 
  

   sugar 
  by 
  yeast, 
  and 
  states 
  that 
  during 
  the 
  recent 
  war 
  certain 
  of 
  

   the 
  belligerent 
  countries 
  have 
  prepared 
  their 
  glycerine 
  indus- 
  

   trially 
  by 
  this 
  method. 
  As 
  early 
  as 
  1857 
  Pasteur 
  found 
  that 
  

   glycerine 
  was 
  formed 
  during 
  alcoholic 
  fermentation, 
  and 
  he 
  

   obtained 
  a 
  yield 
  of 
  3- 
  60 
  to 
  3- 
  64 
  parts 
  for 
  100 
  parts 
  of 
  sugar 
  fer- 
  

   mented. 
  Later 
  it 
  was 
  found 
  by 
  Laborde 
  that 
  the 
  quantity 
  of 
  

   glycerine 
  formed 
  varies 
  with 
  different 
  races 
  of 
  yeast, 
  and 
  obtained 
  

   as 
  much 
  as 
  7-75 
  g. 
  from 
  100 
  g. 
  of 
  sugar. 
  It 
  has 
  been 
  found 
  also 
  

   that 
  the 
  amount 
  of 
  glycerine 
  formed 
  is 
  greater 
  in 
  a 
  medium 
  rich 
  

   in 
  nutritive 
  matters, 
  and 
  less 
  in 
  cases 
  where 
  the 
  conditions 
  are 
  

   less 
  favorable 
  for 
  the 
  growth 
  of 
  the 
  yeast 
  plant. 
  It 
  was 
  evident 
  

   that 
  the 
  amounts 
  of 
  ethyl 
  alcohol 
  and 
  glycerine 
  were 
  not 
  propor- 
  

   tional. 
  

  

  It 
  was 
  supposd 
  by 
  T. 
  Erlich 
  that 
  glycerine 
  could 
  be 
  formed 
  

   from 
  certain 
  acid 
  amines, 
  as 
  is 
  the 
  case 
  with 
  amyl 
  and 
  other 
  

   higher 
  alcohols, 
  and 
  thus 
  its 
  formation 
  was 
  attributed 
  to 
  the 
  fatty 
  

   matter 
  that 
  is 
  found 
  in 
  little 
  droplets 
  in 
  the 
  yeast 
  cells, 
  but 
  it 
  

   was 
  demonstrated 
  later 
  that 
  the 
  quantity 
  of 
  this 
  fat 
  was 
  too 
  small 
  

   to 
  explain 
  the 
  formation. 
  

  

  Oppenheim 
  proved 
  that 
  glycerine 
  can 
  be 
  formed 
  by 
  the 
  reduc- 
  

   tion 
  of 
  glycerine 
  aldehyde 
  and 
  of 
  dioxyacetone, 
  substances 
  that 
  

   are 
  formed 
  during 
  alcoholic 
  fermentation, 
  and 
  various 
  hypotheses 
  

   were 
  made 
  in 
  regard 
  to 
  the 
  intermediate 
  products 
  of 
  the 
  trans- 
  

   formation 
  of 
  sugar 
  into 
  alcohol. 
  It 
  appeared 
  plausible 
  to 
  the 
  

   author 
  that 
  the 
  use 
  of 
  reducing 
  agents 
  in 
  the 
  fermenting 
  liquid 
  

   might 
  increase 
  the 
  yield 
  of 
  glycerine, 
  and 
  accordingly 
  experi- 
  

   ments 
  were 
  made, 
  both 
  in 
  his 
  laboratory 
  and 
  upon 
  a 
  technical 
  

   scale. 
  The 
  greatest 
  difficulty 
  was 
  to 
  find 
  a 
  race 
  of 
  yeast 
  that 
  

   would 
  withstand 
  the 
  conditions, 
  but 
  this 
  was 
  found 
  in 
  a 
  commer- 
  

   cial 
  pressed 
  yeast 
  made 
  from 
  molasses. 
  Powdered 
  zinc 
  in 
  dilute 
  

   sulphuric 
  acid 
  solutions 
  did 
  not 
  give 
  satisfactory 
  results, 
  and 
  

   attempts 
  with 
  acid 
  solutions 
  were 
  abandoned. 
  The 
  reduction 
  in 
  

   solutions 
  as 
  nearly 
  neutral 
  as 
  possible 
  by 
  means 
  of 
  sodium 
  sul- 
  

   phite 
  in 
  the 
  presence 
  of 
  powdered 
  chalk 
  was 
  studied 
  and 
  finally 
  

   led 
  to 
  success, 
  after 
  the 
  proper 
  concentration 
  of 
  the 
  sugar 
  solu- 
  

   tion, 
  the 
  amounts 
  of 
  sulphite 
  and 
  nutrients 
  had 
  been 
  determined. 
  

  

  After 
  dissolving 
  40 
  g. 
  of 
  sugar, 
  2 
  g. 
  of 
  ammonium 
  biphosphate 
  

   and 
  1 
  g. 
  of 
  dipotassium 
  phosphate 
  in 
  400 
  cc. 
  of 
  water, 
  then 
  add- 
  

   ing 
  10 
  g. 
  of 
  pressed 
  yeast, 
  the 
  beginning 
  of 
  the 
  fermentation 
  was 
  

   awaited, 
  and 
  then 
  sodium 
  sulphite 
  to 
  the 
  amount 
  of 
  30 
  g. 
  was 
  

   added. 
  After 
  24 
  hours 
  the 
  fermentation 
  was 
  finished, 
  800 
  cc. 
  of 
  

  

  