MICROSCOPIC GROWTHS IN PHARMACEUTICAL INFUSIONS. 
265 
comparison between an ointment so manipulated and one that has only received 
the ordinary care of the dispenser. In some instances it would be difficult to per¬ 
suade even an experienced eye that the two ointments made from the same ma¬ 
terials, and with equal care, could be identical. 
Lastly, Lard is the basis of most ointments, and therefore by bestowing proper 
attention to the base, we can materially alter the appearance of even those oint¬ 
ments which are not capable of direct filtration. 
The Pharmacopoeial description of the substance to be used is Adeps praepa- 
ratus. “ Qui Sodii Chlorido conditus fuerit, is non adhibeatur.” It is obvious 
that we cannot expect first-class preparations by the employment of the mere 
commercial article as retailed in the shops. 
I have grounds for thinking that the use of water in -preparing Lard is neither 
essential nor desirable, but that its purification may be thoroughly effected by 
the aid of heat. This being an open question, I leave it as it stands. But with 
regard to another point I am most certain, that in whatever way Lard may have 
been purified, it is changed into a beautiful preparation by filtration ; and having 
been once carefully filtered, it may stand its ground against the whole series of 
fanciful amalgams that have been from time to time suggested as a substitute. 
26, St. George’s Place, Hyde Park Corner. 
MICROSCOPIC GROWTHS IN PHARMACEUTICAL INFU¬ 
SIONS, ETC. 
BY MR. CHARLES SYMES. 
Although microscopists have frequently called attention to the appearance of 
organic forms in both vegetable and mineral solutions, the ordinary observer does 
not usually seek for signs of change in these, previous to the appearance of 
mould on the surface, or an abnormal odour and taste. 
Now the presence of most Algae might readily be detected by the naked eye, 
although their structure could not be ascertained without the aid of that valu¬ 
able instrument the microscope; such is the nature of those to which my atten¬ 
tion has been attracted. If either of the subjoined infusions is set aside for a 
few days, or a week, (according to temperature,) there will be found floating near 
or attached to the bottom of the containing vessel one or more small globular 
structures. 
Inf. Rosse Co., Inf. Gentianse Co., Inf. Rhei, and Inf. Calumbse, are those in 
which I have observed them, but they probably occur in many others. They 
consist of a number of fine silky filaments radiating from a common centre, are 
usually separate and symmetrical in form, but occasionally the filaments of two 
are seen united ; this is the appearance to the unaided eye. 
Take now one of these Algae and examine it under the microscope with a one- 
inch object-glass; it is found to form an irregular network in the centre, and 
this contains a number of small bodies, which I at first thought to be nuclei, but 
on further examination they appear to be a collection of particles of the solid 
ingredients which pass through the interstices of the filtering wool, when the in¬ 
fusions are strained. The filaments are usually articulated,* more or less branched, 
and extending to delicate fibrillse. If the solid bodies in the centre are irregular 
in form, the alga is unsymmetrical; thus they appear to influence the growth, 
although forming no essential part of it. 
I hoped to prevent (or at least to relax) their formation by filtering the infu¬ 
sions through paper; this proved ineffectual—they were produced with great 
facility, but without solid particles in the centre. 
* Some of the articulations are not seen with less than a quarter-inch power. 
