TREATMENT OF ASCARIS. 425 



or even green appearance of all objects. As it appears to me, 

 the yellow is essentially the primitive colour, and all other colours 

 depend upon the objects, upon which the patient turns his eyes. 

 "With a cloudy sky, and when the patient turns his eye not to- 

 wards the window, but towards the dimly-lighted back part of 

 the room, he sees all objects pale yellow, as far as I could ob- 

 serve ; and also when he looks at objects strongly illuminated by 

 the sun. If the day be fine and the patient sits at the window, 

 looking at the blue sky, he thinks he sees everything green. 

 At the same time, in quick turning from blue objects or from 

 the blue sky towards objects differently coloured or illuminated, 

 the colour varies through green towards blue and yellow in many 

 ways. I think I have observed these appearances of colour, 

 when I have endeavoured to understand the complaints of the 

 patients. Frightful as these appearances would be to the patient 

 if his attention was not previously called to them, they disturb 

 him but little when we do not omit to inform him of them 

 beforehand. The medical man has nothing to fear from them, 

 these phenomena pass away of themselves within a few hours. 



The physiologists have attempted to account for this phe- 

 nomenon, and it was supposed that there was a yellow colo- 

 ration of the serum of the blood, such as we meet with in 

 jaundice, especially as the urine acquires a similar yellow colour. 

 Zimmermann, of Hanover, gave a young man eight grains of san- 

 tonine from seven to eleven o'clock in the morning. Frequent 

 tears in the eyes soon followed, but ceased about eleven o'clock, 

 and yellow sight, which still persisted at half-past twelve, when 

 some blood was taken from the patient, on account of the occur- 

 rence of congestion of the head. The serum was colourless, and 

 remained so even when heated to 80 F. (30 R.), and on the 

 addition of urine. All other attempts to find a colouring matter 

 analogous to that of the bile have also been in vain, as far as I know. 

 The urine may even be red, or raspberry colour, which often gives 

 great anxiety to the parents, as they regard it as bloody ; it may 

 retain this colour as long as it has an acid reaction, and only become 

 orange-yellow afterwards, but the sclerotica never exhibits a yellow- 

 colour; the urine never presents the well known phenomena 

 of alteration of colour by nitric acid, nor do other appearances of 

 jaundice occur, such as white stools, of the colour of dog's excre- 

 ment. The yellow pigment treated of here, which must be 

 formed on its passage through the body, because santonine does 



