ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
297 
coloured my varnish, yet it is the most colourless I ever saw. It is 
elastic, dries hard and endures the test admirably, and is very tenacious ; 
it is easily prepared in the way described.” 
(6) Miscellaneous. 
Qualitative and Quantitative Microbiochemical Analysis.* * * § — By 
microbiochemical analysis, M. W. Beyerinck means the employing of 
micro-organisms for demonstrating the presence and amount of certain 
substances of fixed composition, and the intention seems to be to obtain 
evidence of the nature of organic fluids from the extract of plants and 
from the products resulting from the action of ferments ; and further to 
ascertain the constituents of very dilute solutions which are suitable for 
microbic growth. 
For the qualitative analysis the auxanographic method f may bo 
employed with advantage. Tho quantitative method depends, in prin- 
ciple, on the transference of the element or conqiound to tho microbic 
substance and the quantitative determination of tho latter by tho 
enumeration of the colonies. 
It would appear that this method is intended to determine tho 
quantity of organic matter in dilute solutions and in drinking water by 
the growth of micro-organisms, and also to ascertain the total amount of 
nitrogen. It is stated that this method is extraordinarily sensitive, but 
the working details are not forthcoming, and without these a new 
method of procedure is difficult to follow. 
Demonstration of Starch and Cellulose.|— Prof. M. Honig recom- 
mends the following process for the demonstration of the presence of 
starch and cellulose, and for tho separation of these two substances from 
one another and from albuminoids. If a mixture of cellulose, starch, 
sugar, and albuminoids is heated with glycerin to 210° C., the cellulose 
undergoes no change, while the starch is transformed into a mixture of 
soluble starch and dextrine, which dissolves completely in hot water into 
a limpid fluid, and can bo again precipitated by a mixture of 5 parts 
alcohol and 1 part ether, and the amount determined. The sugar and 
albuminoids are dissolved, and are not again precipitated by ether and 
alcohol. A practical method is described, founded on this reaction, 
for the determination of cellulose and starch in fibres. 
The Leeuwenhoek Microscopical Club. § — Tho members of this 
private club, at Manchester, have published the records of their pro- 
ceedings from 1867 to 1891. They have found that, for their purposes, 
six or eight persons form thennost convenient numbers for effective con- 
sideration and discussion. The club has always usod the Microscope as 
an accessory to investigation. 
* Centralbl. f. Bakteriol. u. Parasitenk., x. (1891) pp. 723-7. 
t See this Journal, 1891, p. 800. 
1 Verhandl. Naturf. Ver. Briinn, xxix. 1890 (1891) pp. 23-5. 
§ ‘ A Review of the Work of the Leeuwenhoek Microscopical Club, Manchester, 
1867-91.’ 
