ON SACCHARUM LACTIS 205 



to which a receiver was annexed. The retort was placed in 

 a sand-bath. As soon as this mixture acquired a certain 

 degree of heat, it began to effervesce violently ; I therefore 

 took the retort out of the sand, with the receiver, and put 

 it upon the table. The mixture, however, grew hotter and 

 hotter, and the effervescence stronger and stronger, with dark 

 red vapours, and continued to do so for about half an hour 

 upon the table, without any fire. A considerable quantity of 

 nitrous air and aerial acid were extricated during that time. 

 Whoever, therefore, wishes to repeat this experiment, must 

 not take too small a retort, nor lute the retort too tight to 

 the receiver. After the effervescence had subsided in some 

 measure, the retort was again placed in the sand-bath, and 

 the nitrous acid was thus distilled off, till the mass acquired 

 a yellowish colour ; whereupon the retort was immediately 

 taken out of the fire. In two days' time the solution seemed 

 to have undergone no remarkable change ; there was no appear- 

 ance of crystals ; I therefore added 8 oz. more of the same 

 nitrous acid, and exposed it to the same degree of sand heat. 

 As soon as the mass grew warm, the yellow colour dis- 

 appeared, an effervescence ensued as before, though it was 

 not so strong. After it was over, I again abstracted the 

 nitrous acid, till the solution, which meanwhile had been 

 rendered opaque by a white powder, assumed a yellowish 

 colour, whereupon the retort was removed from the sand. 

 After it was grown cool, I found the mass in the retort 

 inspissated ; I therefore redissolved it in 8 oz. of water, and 

 passed the whole through a filter. There remained on the 

 filter a white powder, which, after being edulcorated and 

 dried, weighed 7J drms. The solution which passed through 

 the filter was very sour : I now evaporated it to the con- 

 sistence of a syrup, poured 4 oz. more of nitrous acid on it, 

 and evaporated it again in a sand heat. After the whole 



