BAIRD &TXTLOCK (LONDON) LTD. 



5034 



5035-5044 



5034 s Diaphanometer, designed by Dr. Konig, for determining the degree of turbidity and 



depth of colour of solutions .. .. .. .. .. .. 11 5 



DESCRIPTION. 



This instrument consists of two immersion tubes : the light transmitted by the solution under examination 

 passes through one tube (the right) , the other tube serving as a comparison. The light from both tubes is observed 

 through one eyepiece, each tube lighting one-half the field, after the manner of a half shadow polarimeter. Discs 

 of red and green glass are supplied, to be inserted in the left tube to cut down the light, until it is about equal 

 to that transmitted through the other tube. A series of discs can also be introduced into the path between the 

 left-hand tube and its prism ; these cut off from 10 per cent, and upwards of the transmitted light. The final 

 comparison is made by raising or lowering the right-hand tube. Tables are given for converting the observations 

 into percentages of turbidity or colour for white light, the number obtained actually denoting the percentage of 

 light transmitted by the liquid under observation. The instrument is used in front of a window, the diffused light 

 being reflected into the tubes by a ground-glass plate ; direct sunlight should be avoided. Standard glasses or 

 solutions are not needed with the instrument. The strength of solutions of various coloured salts may be approxi- 

 mately determined. 



5035 T Colorimeter (Autenrieth & Koenigsberger's), large model for chemists, colour, paper and 



textile manufacturers, and brewers. Length of wedge 16 centimetres . . . . 2 14 



5036 T Colorimeter, small model for doctors, pharmaceutical chemists, and preparers of chemical 



foods. Length of wedge 12 centimetres . . . . . . . . . . ..240 



5037 T Colorimeter, small model, with two wedges, for determining Haematin and sugar . . 2 10 



5038 T Drinking Water Outfit, consisting of small Colorimeter with i gauged wedge each for 

 ammonia, nitrous acid, iron, and i empty wedge with stopper for any other kind of 

 colorimetric examination, also with light protection device, all parts in velvet-lined, 

 polished wooden case . . . . . . . . . . . . . . each 5 15 



5039 T Drinking Water Outfit, consisting of small Colorimeter with light protection device, and 

 i gauged wedge each for ammonia, nitrous acid, sulphuretted hydrogen, lead, iron, copper, 

 and 2 wedges, all parts in velvet lined, polished wooden case . . . . each 710 



CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 



921 



