1896.] MICROSCOPICAL JOURNAL 253 



oxalic acid they remain green. The leaves of g-eranium 

 maculatum commonly turn reddish-brown; when pre- 

 served with 3-per-cent of the acid they remain g-reen. The 

 leaves and petals of baptisia tinctoria almost invariably 

 turn black when dried in the ordinary way; when preserved 

 with 3-per-cent oxalic acid, the chang-e is much less pro- 

 nounced and the petals remain yellow. In all specimens 

 the colors of the petals was unchang-ed. 



The results which I have obtained by this process lead 

 me to the conclusion that it may be employed with decided 

 advantag-e in almost all cases, and I will briefly state the^ 

 method I have employed : 



Heavy g'ray felt paper was thoroug^hly saturated with a 

 3-per-cent solution of oxalic acid, and dried. This, when 

 done at ordinary summer temperature, required about 

 twelve hours. Directly between the thus prepared paper 

 I placed the plant ; in case the petals were very delicate, 

 they were protected by a veay thin piece of paper to pre- 

 vent imprints from the roug-h felt paper. The latter was 

 changed once in twenty-four or thirty-six hours, until the 

 plant was thoroughly dried, and it was then mounted in the 

 ordinary way. If possible, the plants should be placed in 

 the press at the time of collection, or carried in an air-tig^ht 

 box and moistened before pressing-. 



Up to the present date I have not had the opportunity of 

 studying- by experiments to what extent plant colors are 

 really injured by ammonia, but I hope to be able to report 

 upon this question at a subsequent date. — American Journal 

 of Pharmacy . 



BACTERIOLOGY. 



Marsh Fever.^ — M. A. Laveran presented a paper at 

 the Academy of Science, Paris, in which he stated that 

 althoug-h the presence of amoeba in the blood during- 

 marsh fever is now well established, there is hardly any 

 g-round for the assumption of a distinct species peculiar to 

 each variety of the disease, one for tertiary ag-ue, another 

 for quaternary ag-ue, and a third g-iving- rise to an irreg-u- 



