Note 71 — COMPARATIVE EXPERIMENTS.

On comparing the corresponding experiments of series XLVIII.–LI. with those of series LIII.–LVI. less difference is found than might have been expected by many. The comparison of the numbers of each series with one another, also reveals the interesting fact, that the mere presence of N, C, O, and H, is not all that is required, even for the growth and nutrition of the lower living things. These elements seem to lapse into the new combinations constituting living matter of various kinds, more easily from certain pre-existing states of combination than from others. Solutions of ammonic tartrate are much more favourable starting points for the new combinations than solutions of ammonic acetate. The comparison of experiment No. LI. with No. LII. is extremely interesting in reference to the dogma that phosphorus is a necessary ingredient in living matter. Solutions of the ammonic tartrate in distilled water have been twice analyzed for me by a skilled chemist, without revealing the least trace either of phosphorus or sulphur. This result is very remarkable when compared with the amount of living matter which may so soon appear in such a solution: the number of the organisms and the rapidity of their evolution, being almost equal to that which occurs in a similar solution to which a phosphate has been added. However much, therefore, phosphorus may aid the development of organisms in many fluids, there is still an important difference between many and all, which if more frequently borne in mind, would render universal propositions more scarce (see ‘Journal of Chemical Society,’ March, 1871, pp. 72–74). The truth of the dictum “Ohne Phosphor gar kein Leben,” is, I venture to think, far from being proved. If on insufficient evidence (referring only to particular fluids) such a dictum is arrived at; and if then, the presence of organisms in any fluid is to be taken as evidence of the existence of phosphorus (even though this cannot be otherwise substantiated), the case of phosphorus in relation to Life comes to be similar to the case of the much abused germs.

Mutato nomine, de te Fabula narratur.