Chemistry and Physics. 399 



SCIENTIFIC INTELLIGENCE 



I. Chemistry and Physics. 



1. Determination of Phosphorus in Phosphor Tin. — Gemmel 

 and Archbutt have devised a new method for making this some- 

 what troublesome determination. They place two to five grams 

 of the sample in a 500 cc Jena flask fitted with a tap funnel and 

 delivery tube. The tap funnel has a two-way stop-cock, allowing 

 gas or liquid to be introduced as desired. The absorption appa- 

 ratus consists of three Drecbsel bottles, the first two charged with 

 bromine and water, the last with bromine water only. The air is 

 first removed by passing carbon dioxide, then 50 to 100 cc of con- 

 centrated hydrochloric acid are introduced, and the contents of 

 the flask gently heated and finally boiled until the substance is 

 dissolved. Finally a current of carbon dioxide is again passed 

 through the apparatus in order to drive forward any remaining 

 traces of hydrogen phosphide, the liquids in the absorption 

 apparatus are transferred to a beaker, evaporated to small volume, 

 and the phosphoric acid is precipitated with magnesium mixture 

 in the usual manner. It is to be observed that any arsenic present 

 in the substance would pass over with the phosphorus, but the 

 authors did not find this element present in the samples that they 

 examined. It was found that the actual evolution and absorption 

 occupies less than twenty minutes, so that the process is shorter 

 and simpler than those usually employed. Upon comparison with 

 the methods consisting in the fusion, with "hepar sulphuris " and 

 with potassium cyanide, of the products of treatment with nitric 

 acid the new method was found to give much more concordant 

 results. — Jour. Soc. Chem. Indus., 1908, 427. h. l. w. 



2. Comjylex Calcium Salts. — By the action of csesiuni sulphate 

 solution upon gypsum, D'Ans has prepared a very stable double 

 sulphate Cs 2 Ca 2 (S0 4 ) 3 . The calcium alkali double sulphates now 

 known, of which the first is the mineral syngenite, are as follows : 



K 2 Ca(S0 4 ) 9 .H 2 K 2 Ca 5 (S0 4 ) 6 .H 2 



(NH 4 ) 2 Ca(S0 4 );.H 2 (NH 4 ) 2 Ca 2 (S0 4 ) 3 (NH 4 ) t Ca.(SOj 6 .H„0 



Rb o Ca(S0 4 ) 2 .H o Rb,Ca 8 (S0 4 ), 



CO;Ca.(S0 4 ), 



D'Ans has prepared also two interesting triple salts analo- 

 gous to polvhalite, Ca 2 MgK 2 (S0 4 ) 4 .2H 2 0. These are the salts 

 Ca 2 Cu(NH 4 ) 2 (S0 4 ) 4 .2H 2 and Ca 2 CdK 2 (S0 4 ) 4 .2H 2 0, which were 

 prepared by boiling solutions of the proper salts with gypsum. 

 It is probable that a considerable number of compounds analogous 

 to polvhalite and to krugite, Ca 4 MgK 2 (S0 4 ) 6 .2H 2 0, may be pre- 

 pared, and it is the author's intention to continue his investigations 

 in this direction. — Perichte, xli,- 1776. h. l. w. 



