480 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
Herr Fr. Kopsch * * * § gives the results of his use of formaldehyde 
antecedent to chrome-silver impregnation. It works well and surely 
even for difficult objects, such as the retina, and the impregnation 
succeeds on material 24 hours or even 48 hours old. 
Retention of the Blood-Colour in Anatomical Preparations by 
means of Formalin.j — Herr L. Jores uses saline solutions instead of 
water for diluting formalin. This mixture not only keeps the blood- 
colour better, but the preparations are also more suited for histo- 
logical investigation. The solution recommended for the mixture is : — 
common salt 1 part, magnesium sulphate 2 parts, sodium sulphate 
2 parts, water 100 parts. In this solution the organs lose their colour 
and assume a dirty blue-grey hue. On pouring off the formalin and 
replacing it by 95 per cent, alcohol, the natural colour slowly returns. 
The objects are then placed in an indifferent preservative fluid, i.e. a 
mixture of glycerin and water. 
Disinfecting Power of Formalin.^ — Dr. H. Strehl found that for- 
malin vapour is not an effective disinfectant when used against a dry 
virus (anthrax, staphylococcus). But when formalin spray is used the 
test objects are killed, and the same result is arrived at even with the 
vapour, if the objects be moistened first. 
Herr Schepilewsky § states that the effect of solutions of formalin 
tested on anthrax is about equal to that of carbolic acid, and about four- 
teen times weaker than sublimate. In the gaseous form the influence of 
formic aldehyde is much stronger than in solution. As a disinfectant 
for articles of furniture, clothing, furs, and those made of metal, it is 
very satisfactory, inasmuch as it does not damage or tarnish them. The 
author’s results are quite in agreement with those of other observers, 
viz. that while formalin is a valuable and effective disinfectant, its action 
may be inoperative on dry material, or where the material is placed in a 
position difficult of access, as between the leaves of books. 
Disinfection with Formic Aldehyde. || — Experiments as to the dis- 
infecting properties of the vapour of formic aldehyde have been made 
under practical conditions by MM. G. Roux and A. Trillatt. The 
vapour was generated in an autoclave, in which commercial formaldehyde 
was heated in presence of a neutral salt. Bardet’s apparatus, by which 
the vapour is produced by the oxidisation of methyl-alcohol, was also 
used. The size of the rooms exposed to the influence of the vapour 
varied from 70 to 1400 cubic metres. The destruction of germs was 
found to be complete. Though the vapour is extremely irritating, there 
is no fear of poisoning from carbonic oxide. 
Dr. F. J. Bose has tested the value of formaldehyde vapour for disin- 
fecting the wards of hospitals for contagious diseases. Trillat’s appa- 
ratus was used for generating the vapour. A five hours’ exposure was 
* Tom. cit., pp. 727-9. 
f Centralbl. f. allg. Pathol, u. Pathol. Anat., vii. (1896) No. 4. See Centralbl. f. 
Bakteriol. u. Parasitenk., l te Abt., xix. (1896) p. 629. 
% Centralbl. f. Bakteriol. u. Parasitenk., l te Abt., xix. (1896) pp. 785-7. 
§ Diss., Petersburg, 1895. See Centralbl. f. Bakteriol. u. Parasitenk., l te Abt., 
xix. (1896) pp. 794-6. 
|| Ann. Inst. Pasteur, x. (1896) pp. 283-96. Tom. cit,., pp. 297-30S. 
