﻿136 
  Scientific 
  Intelligence, 
  

  

  used 
  since 
  its 
  appearance 
  four 
  years 
  ago, 
  now 
  appears 
  in 
  a 
  

   second 
  edition. 
  Many 
  minor 
  changes 
  have 
  been 
  made 
  and 
  a 
  few 
  

   portions 
  have 
  been 
  entirely 
  re-written 
  on 
  account 
  of 
  the 
  advances 
  

   that 
  have 
  been 
  made 
  in 
  the 
  science. 
  

  

  While 
  this 
  text-book 
  is 
  not 
  as 
  large 
  as 
  some 
  others 
  on 
  the 
  sub- 
  

   ject, 
  it 
  gives 
  a 
  very 
  satisfactory 
  and 
  clear 
  presentation 
  of 
  the 
  

   fundamental 
  theories 
  and 
  facts 
  and 
  it 
  is 
  very 
  suitable 
  for 
  its 
  

   intended 
  use 
  in 
  connection 
  with 
  lectures 
  and 
  laboratory 
  prac- 
  

   tice. 
  Many 
  practical 
  applications 
  of 
  organic 
  chemistry 
  are 
  men- 
  

   tioned, 
  so 
  that 
  the 
  student 
  may 
  realize 
  to 
  some 
  extent 
  the 
  part 
  

   played 
  by 
  the 
  science 
  in 
  ordinary 
  life 
  and 
  in 
  our 
  industries. 
  

  

  h. 
  l. 
  w. 
  

  

  6. 
  Sounds 
  Produced 
  by 
  Drops 
  Falling 
  on 
  Water. 
  — 
  It 
  is 
  

   doubtless 
  a 
  matter 
  of 
  common 
  observation 
  that 
  sounds 
  of 
  short 
  

   duration 
  having 
  a 
  musical 
  character 
  are 
  produced 
  when 
  drops 
  

   fall 
  upon 
  the 
  quiescent 
  surface 
  of 
  a 
  relatively 
  large 
  body 
  of 
  

   water. 
  The 
  predominant 
  pitch 
  is 
  low 
  when 
  a 
  large 
  round 
  stone 
  

   is 
  dropped 
  into 
  a 
  stagnant 
  pool, 
  while 
  the 
  sound 
  arising 
  from 
  

   the 
  impact 
  of 
  a 
  bullet, 
  fired 
  from 
  a 
  distant 
  rifle, 
  closely 
  resembles 
  

   that 
  generated 
  by 
  dropping 
  one 
  wooden 
  plank 
  on 
  another. 
  

   In 
  general, 
  the 
  pitch 
  of 
  the 
  note 
  is 
  high 
  at 
  first, 
  then 
  falls, 
  and 
  

   afterward 
  again 
  rises. 
  An 
  account 
  of 
  some 
  experiments 
  per- 
  

   formed 
  along 
  this 
  line 
  has 
  been 
  recently 
  published 
  by 
  A. 
  Mal- 
  

   lock. 
  

  

  The 
  author 
  says: 
  "It 
  seemed 
  probable 
  that 
  the 
  pitch 
  would 
  

   be 
  dependent 
  on 
  the 
  resonance 
  of 
  the 
  cavity 
  formed 
  by 
  the 
  

   impact 
  of 
  the 
  falling 
  drop, 
  and 
  the 
  experiments 
  here 
  described 
  

   were 
  made 
  with 
  the 
  object 
  of 
  determining 
  the 
  magnitude 
  and 
  

   shape 
  of 
  the 
  cavity 
  in 
  question. 
  It 
  was 
  found 
  by 
  trial 
  that 
  the 
  

   same 
  class 
  of 
  sounds 
  were 
  produced 
  whether 
  the 
  falling 
  body 
  was 
  

   a 
  liquid 
  drop 
  or 
  a 
  solid 
  sphere. 
  The 
  experiments, 
  therefore, 
  

   were 
  made 
  with 
  solid 
  spheres, 
  as 
  there 
  is 
  less 
  complexity 
  in 
  the 
  

   displacements 
  caused 
  by 
  them 
  than 
  when 
  the 
  deformation 
  of 
  the 
  

   fluid 
  drop 
  itself 
  enters 
  into 
  the 
  problem/ 
  ' 
  

  

  The 
  experimental 
  method 
  may 
  be 
  broadly 
  outlined 
  as 
  follows. 
  

   Two 
  solid 
  spheres, 
  initially 
  at 
  rest 
  at 
  the 
  same 
  level 
  and 
  having 
  

   equal 
  radii 
  and 
  densities, 
  were 
  released 
  simultaneously 
  by 
  means 
  

   of 
  an 
  electromagnet. 
  One 
  spherical 
  shot 
  fell 
  into 
  water 
  con- 
  

   tained 
  in 
  a 
  rectangular 
  vessel 
  two 
  opposite 
  sides 
  of 
  which 
  were 
  

   made 
  of 
  sheets 
  of 
  plane 
  colorless 
  glass. 
  The 
  other 
  shot 
  tripped 
  

   a 
  key 
  in 
  the 
  circuit 
  of 
  a 
  Ley 
  den 
  jar, 
  spark 
  gap, 
  etc. 
  The 
  photo- 
  

   graphic 
  plate 
  was 
  placed 
  against 
  one 
  of 
  the 
  plane 
  windows 
  of 
  

   the 
  water 
  trough 
  on 
  the 
  side 
  most 
  remote 
  from 
  the 
  spark 
  gap. 
  

   The 
  spark 
  gap 
  was 
  so 
  adjusted 
  as 
  to 
  be 
  at 
  about 
  the 
  same 
  level 
  as 
  

   the 
  free 
  surface 
  of 
  the 
  liquid 
  and 
  on 
  the 
  continuation 
  of 
  the 
  

   normal 
  dropped 
  upon 
  the 
  plane 
  of 
  the 
  gelatin 
  film 
  from 
  the 
  

   point 
  of 
  incidence 
  of 
  the 
  shot 
  at 
  the 
  water 
  surface. 
  In 
  this 
  

   way 
  shadowgraphs 
  of 
  the 
  shot 
  and 
  of 
  its 
  path 
  through 
  the 
  liquid 
  

   were 
  readily 
  obtained. 
  

  

  