70 On file Nature of the clkaline JMaller contained in 



cipitate, but not peniianeiu. The queslioii iiaturaUv arises. 

 What was that noil- permanent precipitate? I have no 

 doubt the quantity was too small to enable the question lo 

 be answertd even by the hands that performed the expe- 

 riment. 



But the cubic and octohedral crystals yielded precipitates 

 with eitl'.er of the two tc?ts ; and hence potash is interred 

 to exist united to nuiriatic acid. I again must appeal to 

 chemical judges, to iletcrmine whether or not the conclu- 

 sion is warrantable; tor, 1. Here is no proof of muriate 

 of potash, e. It is not even certain that the precipitate 

 vvas supertartrate of potash. 3. Granting that supertar- 

 trate of poiasli was produced, it remains to be proved in 

 what state this alkali subsisted. 



4. Of the Serum of the Blood. 



The saline niattrr procured from this fluid did not, with 

 the platina solution, " produce a precipitate sufficiently di- 

 stinct to be conclusive as to the presence of potash ; but, 

 bv means of tartaric acid, a distinct though not abundant 

 precipitate was produced." Further, with nitric acid this 

 saline matter yielded crystals of a '^ rhomboidal form." 

 Again : this matter dissolved in acetic acid, being evapo- 

 rated to dryness, was treated with alcohol and again evapo- 

 rateil : " the residue, contrary to my expectation, exhibited 

 traces of potash ; but the same residue, with nitric acid, 

 yielded rhomboidal, and no prismatic crystals were seen ;" 

 whilst " potash v\ as easily discoverable in the residue, which 

 had now lost its deliquescent quality." I wish to avoid re- 

 petition of objections already oflisred.. although they are 

 ripplical)le in this place, and will only remark : 1. That I 

 cannot admit the figure of such minute crystals, as a deci- 

 sive piopertv ; hut the kind of nitrate compounded might 

 have been ascertained by the test of tartaric acid. 2. 'I"he 

 dissolution of the acetate in alcohol is the most conclusive 

 experiment given in the paper before me; and it has pro- 

 duced apparent enibarrassment. Even as performed it is 

 pretty determinate, and might have become an expcrimen- 

 tuTU er?tfi.i bv prosecuting U a little further. We know 

 fhat acetate of potash is dissoluble in alcohol, and there is 

 no proof that soda united to acetic acid is present ; evea 

 if such a comiiound be dissoluble in alcohol. It has been 

 thought right,' however, to assume an hypothesis, or more 

 truly two hypotheses, lo account for the potash in thcmen- 

 j>tiuuni of alcohol; viz. — 1. To iuiagine that muriate of 

 potash 15 present. '2. That it is dissoluble in alcohol, li 



potash 



