In order to ascertain the phosphorus, I put 10 grains of well preserved phosphuret of lime, into 1000 grains of liquid oxymuriate of lime, such that by previous trials I knew would impart 3.5 grains of oxygen; to this mixture a quantity of muriatic acid was put, sufficient to engage the lime; the phosphuretted hydrogen disengaged, was of course made to pass through the liquid as it was generated, and became oxidized, so as to lose its gaseous form; the surplus gas was prevented from escaping by an inclination of the bottle; it was 45 grain measures only, and of this 30 were found to be pure hydrogen, and the rest atmospheric air detached from the water; these 30 measures were the _free_ hydrogen, which would have been mixed with the phosphuretted hydrogen, in the ordinary way. In due time, the whole of the phosphuret of lime was dissolved. The liquid was strongly acid, and manifested no smell of oxymuriatic acid, a proof that it was all decomposed. To this were added 70 more of the oxymuriate of lime before the smell of it was permanently developed. The liquid was next saturated with lime water, and the phosphate of lime carefully collected and dried; when heated to a low red it weighed 12 grains, and consisted, according to my estimate of this compound, of 6-- grains of phosphoric acid and 6 + grains of lime. The 6-- grains of acid contained 2.4 phosphorus and 3.5 of oxygen. It must be remembered that 10 grains of phosphuret yield about 500 measures of phosphuretted hydrogen, and these contain 650 measures of hydrogen, which last is also oxidized at the expence of the oxymuriatic acid; but then there is an equivalent of oxygen from the water, so that this does not influence the calculation for oxygen. There appears then to be only an excess of .24 grains of oxygen unaccounted for, (arising from the additional 70 of oxymuriate of lime), which is as little as can be expected in such an experiment. If the phosphorus amount to 24 per cent. we may reasonably infer that the remainder (76) is mostly lime, though I have not been able to detect above 60. Now if an atom of phosphorus weigh 9⅓ and one of lime 24, the due proportion of the protophosphuret of lime would be 28 phosphorus and 72 lime; but when the article is made for sale, it is more likely to find a defect than an excess of phosphorus.