ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
481 
found to be sufficient for destroying pathogenic germs, provided the 
vapour had free access, even though the space was large (737 cubic 
metres). If too much covered, as by heaping up of cloths, or by con- 
cealment in pockets of dresses, &c., the action of the vapour was less 
successful. The bacillus of tubercle, either in the wet or dry condition, 
were easily killed. No damage was done to any of the articles in the 
places disinfected. 
Media for Preserving Algae.* — Prof. W. A. Setchell and Mr. W. J. 
Y. Osterhout give the results of their experience in the use of the follow- 
ing media for preserving algse for class-material: -chrome-alum, formalin, 
and camphor-water. The Cyanophyceae are best prepared with a solu- 
tion containing 1 per cent, chrome-alum and 1 per cent, formalin ; this 
solution renders the gelatinous sheath and matrix firm, and retains in 
most cases the colours in their ordinary tints. The Chlorophyceae are 
very satisfactorily preserved in any of these media ; chrome-alum is to 
be preferred in most cases, but some species, such as Ulva Lactuca , are 
rendered very brittle. Such forms are better preserved in formalin. 
The Phseophyceae do well if placed immediately in 1 per cent, formalin 
in sea- water ; the larger forms are better fixed in the 1 per cent, chrome- 
alum for a few hours, and then preserved in 2 per cent, formalin solu- 
tion or camphor- water. The coarser forms of the Florideas may be put 
into any one of the three solutions, and will be found in very excellent 
condition ; chrome-alum preserves the colour better than formalin or 
camphor- water. Very delicate species, like Griffithsia Bornetiana , may 
be placed in 2 per cent, formalin in sea-water, when the cells keep their 
shape, and the whole plant preserves a life-like appearance, though the 
colour disappears. 
Preserving and Mounting Fluids for Algse and Mosses.f — M. J. 
Amann recommends the following fluids for preserving and imbedding 
mosses, Ohloro-, and Cyanophyceae : 
(1) Lactophenol. Crystal, carbolic acid, 20 grm. ; lactic acid sp.gr. 
1*21, 20 grm. ; glycerin sp. gr. 1*25, 40 grm.; distilled water, 20 grm. 
(2) Lactophenol-copper solution. Crystal, copper chloride CuCl 2 , 
0*2 grm.; copper acetate CuC 4 H 6 0 4 , 0*2 grm. Dissolved in lacto- 
phenol, 5 grm. ; distilled water, 95 grm. 
(3) The foregoing solution concentrated ten times is very useful for 
excursion work. The water containing the algse is merely diluted with 
5-10 per cent, of the strong solution, the formula for which is copper 
chloride, 2 grm. ; copper acetate, 2 grm. ; lactophenol, 96 grm. 
(4) Glycerin-gelatin, with lactophenol. White gelatin, 8 grm. ; 
distilled water, 44 grm. After the gelatin has been thoroughly soaked, 
glycerin sp. gr. 1*25, 30 grm. are added, and the whole boiled in a 
water bath ; after filtration 10 grm. of lactophenol are added. This 
medium is a better substitute for Canada balsam than the ordinary 
phenol-glycerin-gelatin. 
(5) Glycerin-gelatin, with copper solution, is prepared like No. 4, 
but instead of the lactophenol, 10 per cent, lactophenol-copper solution 
(No. 3) is substituted. 
* Bot. Gazette, xxi. (1896) pp. 140-5. 
t Zeitschr. f. wiss. Mikr., xiii. (1896) pp. 18-21. 
