RESEARCHES UPON SALTCIN. 
159 
tals, he supposed to differ from salicin. I have examined this 
body and cannot detect any difference between it and salicin, 
sulphuric and nitric acids, the alkalies, &c, and analysis affords 
the same results as with crystals of salicin. 
I may, however, remark that this substance is not always 
produced. I have seen salicin which when thus treated con- 
stantly yielded this modification, and some which as uniformly 
gave the common form of salicin. 
Braconnot found, lik ewise, that concentrated sulphuric and 
hydrochloric acids changed salicin into aspecies of resin, which 
was deposited on the addition of water. I also find that 
many acids, even when dilute, effect this change, if heated to 
ebullition, the resin rising to the surface. It is sometimes 
white, but often slightly yellow, and has all the characters of 
that obtained by cold concentrated acid. I call this body sali- 
retin. It varies in purity according to the purity of the salicin 
used ; the more dilute the acid, the purer is the product ob- 
tained. 
Saliretin is insoluble in water and ammonia, soluble in alco- 
hol, ether, and concentrated acetic acid. Water precipi- 
tates it from these solutions. Potassa and soda dissolve it, but 
water does not throw it down, while acids, even the carbonic, 
precipitate it as a white gelatinous mass. 
Concentrated sulphuric acid put in contact with saliretin be- 
comes blood red. With strong nitric acid, it is, by boiling, 
changed into carbazotic acid. 
The following analytic results are from a perfectly colorless 
product: 
I. 0.504 saliretin, gave 0.264 water and 1.249 carbonic acid. 
II. 0.309 " " 0.168 " and 0.776 " " 
III. 0.380 " " 0.947 carbonic acid. 
From another product the analytic results were-— 
IV. 0.369 saliretin gave 0.194 waterand 0.973'carbonic acid. 
V. 0.413 " " 0.214 " and 1.089 " " 
VI. 0.349 " « 0.189 " 
From which data the composition in hundredths would be — 
