220 
NATURE 
[Faly 14, 1870 
ments necessary for the building up of organic substances, Nitro- 
gen, carbon, hydrogen, and oxygen are there, and only require to 
fall into other modes of collocation in order to give birth to an 
organisable material. The crystals of the oxalate are very small, 
those of the acetate are very deliquescent, and carbonate of 
ammonia exists generally in the form of non-crystalline cakes. * 
The neutral tartrate, however, exists in the form of large dis- 
tinct prismatic crystals. Solutions of the first three substances 
showed no trace of Living things; though organisms were fre- 
quently discovered when crystals of tartrate of ammonia were 
examined, 
Before describing these organisms more particularly, it will be 
well to glance for a moment at the origin or mode of prepara- 
tion of this salt. The tartaric acid entering into its composition 
is obtained from avgo/—the crude bitartrate of potash derived 
from the grape. And although this latter salt is derived from the 
tissues of a Living plant, the processes to which it is submitted, 
in order to obtain the tartaric acid in an uncombined 
state, would most certainly destroy all living ‘‘ germs” that 
might have been contained therein. After a solution of 
the bitartrate of potash has been boiled for a time, tartrate of lime 
is gradually precipitated by the addition of chalk and chloride of 
calcium. The insoluble tartrate of lime, after having been washed 
several times, is then brought into contact with strong sulphuric 
acid, diluted with only about four times its bulk of water, 
and this mixture is boiled for half an hour.+ All this is neces- 
sary before a filtrate can be obtained from which the first crystals 
of tartaric acid are procurable. Ammonia, the other constituent 
of the neutral tartrate, being a product of the destructive distil- 
lation of coal tar, and itself exercising such a destructive influence 
upon organic matter when existing in the form of strong /iguor 
ammonia, would not seem to be a yery promising nidus for 
organic ‘‘ germs.” ‘The neutral tartrate of ammonia is, however, 
prepared by mixing a solution of tartaric acid, procured as 
above mentioned, with an adequate quantity of liquor ammonize, 
and then evaporating the mixture at a gentle heat, Thus pre- 
pared, the crystals contain a notable quantity of water of crystal- 
lisation, and are not specially liable to contain organic impurities. 
In the stock of crystals that I obtained from Messrs. Hopkin 
and Williams,$ and which had been made about six months 
previously, some were well formed, and almost perfectly 
transparent, whilst others were less regular in shape, and 
presented an opaque appearance with more or less of striation 
within. When a crystal of moderate size was taken, about 4” 
in diameter, or a portion of a larger one, and was placed ina 
large watch-glass with some distilled water, it was frequently 
found that at first a certain number of opaque-white scales, 
having a granular aspect under a high magnifying power, dropped 
from the surface of the crystal to the bottom of the watch-glass. 
This material, which seemed to haye been produced by some 
superficial alteration of the substance of the salt, dissolved 
with much more difficulty than the unaltered matter of the crystal. 
It remained for a long time at the bottom of the glass, and only 
very slowly disappeared. As the substance of the crystal slowly 
dissolved away, a number of large and small gaseous bubbles 
gradually escaped from it. When the crystal was examined 
with a one-inch object-glass whilst solution was taking place, 
these air bubbles could be seen at first within cavities, from 
which they were afterwards liberated by a solution of their walls. 
Occasionally, from the very centre of a crystal, from which 
bubbles of gas had been escaping, there floated out a very small 
and almost invisible filamentary mass, more or less thickly 
studded with minute air bubbles. Such masses were just 
visible with an ordinary pocket-lens, and when transferred on 
the point of a needle to a slip of glass, and examined with 
a magnifying power of about 600 diameters, they were found 
to contain more or less of the following constituents : — 
(1) a minute fragment cf cotton or paper fibre; (2) a variable 
quantity of an almost transparent, insoluble plate-like substance, 
homogeneous, though broken up in all directions by intersecting 
cracks ; (3) more rarely a small quantity of a tenacious mucoid 
matter, containing refractive protein-looking granules of various 
sizes ; (4) a quantity of a colourless, confervoid-looking mass, some 
ot whose smaller filaments, s45y” in diameter, looked like a mere 
linear aggregation of irregular masses of protoplasm, though in 
* Obtained by a process of sublimation at high temperatures. 
+ The boiling point of such a solution would be several degrees above 100? 
C. Heat and acid combined exercise a most powerfully destructive influence 
upon organic matter, though even very dilute sulphuric acid, at ordinary tem- 
peratures, has been found to be peculiarly destructive to all Living things. 
t Of New Cavendish Street, 
certain larger filaments continuous with these it became obvious 
that the irregular protoplasm masses were contained within a 
delicate hyaline cylinder across which dissepiments were some- 
times to be seen, as in very minute fungus-filaments ; (5) and lastly, 
certain fungus-spores in almost all respects similar to those which 
have been met with in so many of the saline experimental fluids. 
Although four or five of these were frequently interspersed 
amongst the confervoid-looking filaments, they did not seem to 
be in organic connection with them, The confervoid-looking, 
though really abortive fungus-filaments, were also almost pre- 
cisely similar to the filaments containing irregular masses of 
protoplasm which were met with (in Experiments 12 and 13), in 
solutions containing tartrate of ammonia. 
Repeated examination of crystals during their dissolution con- 
vinced me that such organic bodies invariably came from the 
interior of the crystal, often from its very centre, and that they 
were not to be met with on its surface. Seeing, however, that 
minute shreds of cotton or paper fibre also as frequently came 
from the interior of the crystal,* it was obviously possible that 
the organisms met with might have been engaged mechanically 
during the process of crystallisation, just as it must have happened 
with the shreds above mentioned. From what has previously 
been stated concerning the mode of preparation of the neutral 
tartrate of ammonia and the origin of its constituents, it may be 
considered almost certain that these organisms could not have pre- 
existed in the strong /igvor ammonia, and that all living organisms 
which might by chance have been associated with the bitartrate 
of potash must have been hopelessly destroyed by the boiling 
with sulphuric acid, which occurred at one stage in the process 
employed for the separation of the tartaric acid from its base. 
During the subsequent process of crystallisation of the tartaric 
acid from its mother liquor, it is of course possible that any spores 
existing in the adjacent atmosphere might have dropped into the 
fluid, and have then become mechanically enclosed within the 
crystals; and the same chance of such a contamination with spores 
would exist during the process of crystallisation of the tartrate of 
ammonia itself. If this, however, had been the real source of the 
fungus-spores and masses of confervoid-looking filaments, such 
bodies might be found in freshly prepared crystals just as well as 
in those which had existed for six months.t I therefore asked 
Messrs. Hopkin and Williams to prepare for mea fresh batch of 
crystals of neutral tartrate of ammonia. This they were kind 
enough to do; obtaining them in the same place by the same 
process, and exposing the mother liquor in a precisely similar 
way. 
An examination of some of these crystals, whilst they were 
being dissolved by distilled water in a watch-glass, showed 
that (unlike the older crystals) they were not at all coated on the 
surface by the comparatively insoluble granular plates ; and that 
only a few very small air bubbles emerged from their interior, And 
at the bottom of the watch-glass, neither during dissolution nor 
afterwards, was there seen any trace of the confervoid-looking 
filaments or of the fungus-spores, though minute shreds of cotton 
and paper fibres were seen similar to those which were found in 
theolder crystals. An examination of a large number of the new 
crystals was attended with similar results to those just mentioned. 
This absence of the con/fervoid-looking filaments and of the 
large fungus-spores from the recently prepared crystals may be 
accounted for by either one of two suppositions :— 
First. It may be supposed that in the case of the older crystals, 
the spores and filaments had dropped as such into the solutions 
in which the tartaric acid alone, or the tartrate of ammonia was 
crystallising; that they were mechanically engaged in the crystals, 
and were subsequently liberated unchanged (without having 
undergone any growth or development) on the dissolution of the 
erystal.t Whilst, on the other hand, in the case of the recent 
crystals, it may have happened that no such filaments ar spores 
were floating in the atmosphere at the time of ¢/er formation, 
and that, consequently, none could have dropped into the solu- 
tions. ence none of these could have been enclosed within 
the crystals, 
* I had often been surprised at finding such shreds when I submitted 
some of my experimental fluids to microscopical examination, knowing 
that I had frequently used freshly prepared distilled water, and had taken 
every precaution thoroughly to cleanse the flasks which were employed. 
+ I have been unable to obtain crystals of the neutral tartrate of am- 
monia of an older date than this, and I should feel much obliged to any one 
who could send me such specimens, or who could furnish me with a few 
crystals of carbonate of ammonia. 
{ Ifthey had been engaged within the crystals of tartaricacid, they must 
have been liberated from these during the preparation of the neutral tartrate, 
only to be re-entangled whilst the crystals of this salt were forming. 
