200 BULLETIN OF THE BUSSEY INSTITUTION. 
show that, in preparing ashes for analysis, some phosphorus will be lost, 
by way of volatilization, unless an abundant supply of air is kept 
constantly in contact with the carbonized vegetable matter, when it 
comes to be ignited. The risk of losing phosphorus in this way has 
been admitted, and dwelt upon by H. Rose, Strecker, Wolff, and other 
chemists who have had to do with ash analysis. Rose,* in particular, 
has shown, by direct experiment, that much phosphoric acid may be 
lost, by way of volatilization, when charcoal that contains an alkaline 
phosphate is calcined. 
Schleesing fT has even gone so far as to base a method for the quan- 
titative estimation of phosphorus upon the fact that the whole of 
this substance can be expelled from phosphate of lime, phosphate 
of magnesia, and the allied phosphates, by heating an intimate mix- 
ture of the phosphate and silica white-hot in a current of carbonic 
oxide. 
Braconnot £ noticed, further, that soot from wood fires contains an 
appreciable quantity of phosphoric acid. In a sample of soft, pulveru- 
lent soot, taken from the middle of a chimney, he found nearly three- 
quarters of one per cent of phosphoric acid. 
As a matter of fact, when reducing wood or any other vegetable 
matter to ashes, with the view of analyzing the latter, chemists have 
long recognized the necessity of operating upon small quantities of the 
material at comparatively low temperatures, and under such conditions 
that there shall be free access of air, in order to avoid, in so far as may 
be practicable, the reducing action of the organic matter. It is not 
impossible, for that matter, that some phosphorus may be lost in com- 
bination with hydrogen during the process of distillation, to which, in 
every fire, some part of the fuel is necessarily exposed.§ 
Besides the waste, by way of volatilization, a certain amount of phos- 
phorus is undoubtedly lost in the form of a compound, insoluble in acids, 
that remains with the ‘‘ sand and charcoal,’’ in an ordinary analysis. I 
find that phosphoric acid can readily be detected in the mixtures of sand 
and charcoal from household ashes that have resisted the action of strong 
chlorhydric acid. This observation is in accord with the experience of H. 
* Poggendorff’s ‘‘ Annalen,” 1850, 79, pp. 421, 422. Compare ibid., '76. 334. 
t Liebig & Kopp’s ‘“‘ Jahresbericht,” 1864, 17. 692, from “‘ Comptes Rendus,” 
59. 384. 
t ‘ Annales de Chimie et de Physique,” 1826, 31. 37. 
§ Compare Violette, ‘‘ Annales de Chimie et de Physique,” 1851, 32. 332. 
