*No. XLVII.--Hay Infusion + 1/20 part of Carbolic Acid* showed no apparent change for the first four days. On the fifth day there was a small quantity of powder-like sediment, and one dirty greyish-coloured flake. On the seventh day there were more small flakes at the bottom, and a slight general turbidity of the fluid. On the twelfth day, the turbidity and deposit having increased, the flask was opened--after it had been first ascertained that the vacuum had only been slightly impaired. The re-action of the fluid was still strongly acid. On microscopical examination of some of the deposit, there was found, amongst granular flakes and aggregations, a large number of _Torulæ_ cells, of most various shapes and sizes; also in the midst of the granule heaps many large, rounded or ovoidal, densely granular nucleated bodies, whose average size was 1/1500″ in diameter, though there were many of them much larger, and others even less than half this size. Intertwined amongst the granular matter also were a large number of algoid-looking filaments, 1/20000 in diameter, containing segmented protoplasmic contents. There were also in the fluid itself a number of medium-size, unsegmented _Bacteria_, whose movements were somewhat languid.[69] [69] The results of this experiment, and of No. LXIII. are decidedly opposed to the reality of the germ-killing powers with which carbolic acid has been endowed by Professor Lister and others. I, however, had previously found that specimens of _Torulæ_ and _Bacteria_, obtained from freshly opened flasks, and then mounted as microscopical specimens in a mixture of glycerine and carbolic acid (in the proportion of 15:1), not unfrequently grew and multiplied under such conditions. MM. Béchamp and Estor, also found that _Bacteria_ multiplied in carbolized fluids, and similar facts have been testified to by some Italian observers. But, organic fluids differ much from one another, so that the influence of carbolic acid may well be different upon different fluids. And, accordingly, we find that whilst its addition to, and subsequent boiling with, a hay infusion increases the fermentability of this, precisely the opposite effects are produced when the hay is replaced by a turnip infusion (see No. XLV.). Without wishing to undervalue in the least the system of treatment introduced, and so admirably carried out by Professor Lister, I am strongly of opinion that he explains his results by theories which are almost wholly incorrect. SIXTH SET OF EXPERIMENTS (XLVIII.–LXV.). _Ammoniacal Solutions, unboiled, and exposed to Ordinary Air in a Corked Bottle._[70] (_Temp. 60°–65° F._) [70] All the simple ammoniacal solutions were in the proportion of ten grains of the salt to the fluid ounce of distilled water; and to those which also contained sodic phosphate, three grains of this were added. About half an ounce of each solution was put into a one-ounce wide-mouthed bottle, and then tightly corked.