406 THALLINE AND PYRIDINE 



series are safer and more effectual, for quinoline is very 

 apt to cause collapse. Dogs and cats, receiving three to 

 six grains per kilogramme of body weight, exhibit increased 

 secretion of saliva and bile, and suffer from vomiting and 

 general enfeeblement. 



TfiALLINE is a synthetically prepared base chemically 

 known as tetrahydroparamethyl-oxy quinoline. It is crys- 

 talline and colourless, has a piquant, bitter, anise-like taste, 

 is soluble in seven parts of cold water and a hundred of 

 alcohol. Both the watery and alcoholic solutions are in- 

 flammable. It combines with acids, and is used as a sul- 

 phate or acetate. It is antiseptic and antipyretic. It 

 resembles antifebrin, but Brunton considers it is less 

 effectual. T. Eraser regards it as probably the most 

 trustworthy antipyretic of the series. Kaufmann and 

 others testify to its febrifuge effects on veterinary patients, 

 and state that it causes neither digestive nor nervous dis- 

 turbance. Moderate doses given to horses and dogs, in 

 one hour reduce abnormal temperature 3 Cent., and such 

 reduction is stated to be maintained for several hours. It 

 slows respiration, diminishes the number of the pulsations, 

 and lessens arterial pressure. These effects appear to 

 depend upon the depression of the heat regulating nerve 

 centres with consequent increased loss of heat by way of 

 the dilated skin vessels. Thalline is stated to communicate 

 a dark-red colour to the blood, from the formation of 

 methaemoglobin, and sometimes causes a red eruption on 

 the tongue (Kaufmann). It is slowly excreted in the urine, 

 which acquires a greenish-brown hue, and is coloured purple 

 by ferric chloride solution. Friedberger prescribes it in 

 contagious pneumonia in horses, both by the mouth and 

 hypodermically. Horses take ^L to ^iii. ; cattle, ^ii. to 

 3iv. ; sheep and pigs, grs. xv. to grs. xxx. ; dogs, grs. ii. 

 to grs. vi., cats, gr. i. to grs. ii., given, as the sulphate, in 

 bolus or solution. Hypodermically, one-third of those doses 

 may be given. 



PYRIDINE (C 5 H 5 N) is obtained from the destructive dis- 

 tillation of bones and other organic substances, and is one 

 of the empyreumatic constituents of tobacco smoke. It 

 is a typical member of the alkali-like bases found in coal- 



