ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
417 
antiseptics possessed greater antibacterial power than any one of the 
components taken singly, points out that the method of examination had 
not been free from objection, and the results were without any special 
practical value, inasmuch as the antiseptics had been used of such strength 
as would preclude their application to the living organism. Yersin was 
the first to adopt a satisfactory method, and the author has followed his 
procedure. 
Phenol and salicylic acid formed the basis of the mixture, the 
presence of the former increasing the solubility of the latter. By the 
addition of organic acids a still further increase of the bactericidal 
properties of the mixture was attained, as was shown by its action on 
St. pyogenes aureus. 
In one table is shown the superiority of this kind of mixtures over 
all known antiseptics, with the exception of sublimate, and in a second 
table are given the different degrees of concentration of “ phenosalyl ” 
necessary for destroying different species of bacteria, St. pyogenes aureus 
being the most refractory. 
Determination of Pectic Substances in Plants.* — M. L. Mangin 
recommends for this purpose the action on thin slices of tissue of a 
mixture of naphthylene-blue and acid green, which gives a double 
staining reaction, the acid green being fixed by the nitrogenous sub- 
stances lignin and suberin, while the pectic substances are stained violet 
by the naphthylene-blue. The preparation should first be neutralized, 
after washing with 1*5 per cent, acetic acid. The presence of pectic 
acid can be demonstrated by separating it from its base by the action 
on very small pieces of tissue of dilute hydrochloric acid or a mixture of 
1/4 acid and 3/4 alcohol. Pectic acid is quite insoluble in water; it 
can be dissolved out by the action of a weak alkali, and then precipitated 
in gelatinous flakes by a weak acid. The ill-defined substance known 
as pectose, which remains behind after the action of the alkali, is not 
readily isolated. 
* Journ. de Bot. (Morot), vi. (1892) pp. 363-8. 
2 F 
1893. 
