426 PHOSPHOROUS ACIDS. 



(b.) Place slicks of phosphorus in a glass funnel, standing in the 

 mouth of a bottle ; a heavy acid vapor falls in a white current, and 

 becomes liquid by deliquescence.* 



The phosphorus is increased in weight, by that of the oxygen and 

 water imbibed, and 1 part thus produces 3 or 4 of phosphorous acid. 

 It is found, kowever, that the product is not, as was formerly suppo- 

 sed, phosphorous acid alone. 



Sir H. Davy found it to be a mixture of phosphorous and phos- 

 phoric acids ; but it is suggested by Murray that it is, when first form- 

 ed, wholly phosphoric acid, but that in condensing it unites with more 

 oxygen and becomes, in part, phosphoric acid. It appears probable 

 that there is a definite compound of phosphorus and oxygen, forming 

 phosphorous acid, although as obtained by deliquescence, the two 

 acids are present in mixture. 



3. PROPERTIES of this mixed acid.\ 



(a.) A transparent dense fluid, viscid, adhering to the glass like 

 oil, but possessing various degrees of density as it has imbibed more 

 or less water. 



(b.) It reddens dark vegetable colors, and sets the teeth on edge. 



(c.) When heated, a part of the water is evaporated, and it emits 

 a white dense smoke, of an alliaceous odor, which in the open air, 

 takes fire with a vivid flash ; and the substance becomes entirely 

 phosphoric acid. 



Sd.) This acid combines with water in every proportion. 

 e.) Aided by heat, nitric acid readily converts this acid into phos- 

 phoric acid ; proportions, 1 of the phosphorous acid, to 8 of the ni- 

 trous, of the sp. gr. 1.3. This is perhaps the best process for ob- 

 taining pure phosphoric acid. 



USES IN MEDICINE, &c. Valuable as a remedy against uterine 

 hoemorrhage, in parturition. J Probably it would act also as a tonic. 



OTHER MODES OF COMBINING PHOSPHORUS WITH OXYGEN. 



(a.) Every person conversant with phosphorus must have observ- 

 ed that when it is kept immersed in water, the air not being entirely 

 excluded, it is slowly oxygenized ; and the water becomes acid. 



* This simple arrangement is sufficient, but Fourcroy recommends to place the 

 phosphorus in glass tubes, wide open at top, and capillary at the bottom ; their points 

 converge in the throat of a large glass funnel ; they are thus secured from taking 

 fire; the funnel is placed in a bottle, the bottle on a plate having water in it, and 

 over the whole stands a glass receiver, with two apertures at its sides, to regulate 

 the admission of the air ; the bottom of the receiver is immersed in the water. This 

 .arrangement I have tried ; it is neat and effectual, but more complex than is necessary. 



t Dulong calls the acid thus obtained the phosphatic, regarding it as a distinct 

 compound, (Phil. Mag. XLVIII, 273,) but this opinion is not generally adopted. 



t Used by the late eminent Dr. Eneas Munson, of New Haven, who practised 

 medicine with great success for 60 years. I used to supply him with this acid, and 

 his language was, that it operated in such cases, like a charm. 



