670 THE ANIMAL PARASITES OF MAN 



morning the patient should take a cup of black coffee or tea without 

 anything else, and half an hour later the vermifuge. 



The best drug is extract, filicis maris aether., which also forms the 

 main constituent of most of the secret remedies recommended for 

 tapeworms. Earlier mishaps with this preparation had their origin 

 principally in insufficient dosage. Also, in addition to correct dosage, 

 extract, rilic. maris needs very careful preparation if satisfactory results 

 are to be attained. If preparations with the trade mark " Helfenberg " 

 or "Wohnar" are not used, but the male fern extract has been 

 prepared by a chemist, one must make certain that the roots of the 

 Aspidhtm filix-mas have been collected in May or October, and only 

 green sappy specimens selected, and that the attached paleae have 

 been separated, that they have been broken up small and ether 

 poured over them with a little spirits of wine while quite fresh. The 

 whole mass is to be kept in a cool place, but not too closely covered. 

 If at any time a certain quantity is to be used, it is taken out, the 

 ether carefully distilled in a retort till the extract has a suitable fluid 

 consistency. Fischer attaches great importance to the direction in 

 the Pharmacopoeia being exactly followed, to the effect that the 

 extract is to be carefully stirred before prescribing, as the active sub- 

 stances undergo partial crystallization if kept for any length of time 

 and sink to the bottom, so that the preparation has a different strength 

 and toxicity in different layers. Of this extract 10 to 12 to 15 grm. are 

 to be taken in gelatine capsules within half an hour. We consider it 

 unjustifiable to give greater doses than 15 grm. to adults, as many 

 cases are known in which to some extent severe toxic symptoms have 

 followed, such as headache, sensation of giddiness, dyspnoea and 

 cyanosis, yellow vision (xanthopsia), delirium, stupor, the most severe 

 cramps in the extremities, rapidly fatal trismus and tetanus. The 

 most serious are defects of vision of various kinds, which may end 

 in amblyopia and amaurosis, with permanent blindness. A complete 

 collection of toxicological literature up to the year 1903 is to be 

 found in Marx's 1 Dissertation. Since that time further instances 

 of such intoxications have been made known. Nagel 2 observed 

 them only in severe cases. O. Meyer 3 lays special stress on the bad 

 prognosis of the disturbances of vision evoked by poisoning with 

 extract, filicis maris. Studt 4 has seen two cases of optic neuritis, one 

 with circumscribed, the other with diffuse retinal oedema. UhthorP 

 has only seen one case ; in that reported by Noiszewski 6 the toxic 

 retinitis was cured; in Viereck's 7 case bilateral concentric limitation 



1 Marx, " Diss. Wiirzburg," 1903. 2 Nagel, Dcutsch. med. Wochcnschr., 1903. 



3 Meyer, O., Berl. klin. Wochenschr., 1905. ' Studt, ibid., 1905. 



5 Uhthoff, ibia.i 1905. a Noiszewski, " Postepokuhs'," 190^. 



1 Viereck, Arch. f. Schiffs- ti. Tropen-Hyg., 1906. 



