EDITORIAL. 
93 
from the labyrinth of theories, and keep within the range of the more im- 
portant facts. It cannot be expected that he shall become a chemist by 
listening to the lectures, and witnessing the few experiments of two medi- 
cal courses; and the home study which he should give to the subject, should 
be assisted by a text book of the most simplified and lucid character. The 
book of Professor Gregory, therefore, whilst it bears on its face the most 
undoubted evidence of the ability and talent of its author, is in our opinion 
not as well fitted for a text book for medical students, as- are less elaborate 
works. 
The duty of an editor in revising a book should be to bring it up to the 
level of the progress of discovery at the time of issue — and as four years 
have elapsed since the last foreign edition was published, we naturally look 
for additions, which are not to be found in the foot notes of the editor, nor 
in the text, and several of which are important. 
In looking over the notes, at page 75, the mode of accounting for the great- 
er solubility of caustic lime in cold than in hot water, by attributing it to 
carbonic acid present in the former liquid, is eertainly novel ! 
Again, we perceive at pages 426 and 430, notices of certain compounds 
of citric and tartaric acid with sesquioxide of iron, and the bases quinia, 
morphia and salicin (!) so as to form double salts. Professor Sanders says, 
salicin is a weak base, but will, under favorable circumstances, form salts 
with acids, and acid radicals. At page 363 in the text, salicin is called 
a neutral body, and is analogous to sugar. We presume that sugar, 
starch or gum, have equal claims to basic power, and a ferrotartrate of ara- 
bin might be made. In fact the amorphous character of the salts of citric and 
tartaric acids with sesquioxide of iron alone or shared with other bases, gives 
ample opportunity to associate any soluble compatible body with those 
acids, which may then be saturated with sesquioxide of iron, and evaporated 
on glass to obtain the mixture in scales. The ferrotartrates and citrates of 
iron with quinia and morphia are recommended to be made by adding the 
pure alkalies to a saturated solution of citric and tartaric acids, and neu- 
tralizing the solution with hydrated sesquioxide of iron. As no chemical 
formulae are given for these compounds, we naturally ask how much morphia? 
how much quinia? In a work of acknowledged accuracy, it is to be regret- 
ted that such loose statements should gain admission. The note at page 
474 on Resinoids, both as regards the discovery and the nature of these prin- 
ciples, is inaccurate, and we think, notwithstanding the opinion of its writer, 
that a long time will elapse ere " active principles analogous to the alka- 
loids in nux vomica, opium, &c.," will be found in these so called resinoids. 
In almost every instance yet investigated, natural vegetable alkalies exist in 
combination with an excess of acids, so as to be soluble in water. Nareotin 
is partially an exception. The best known of the substances in question, 
podophyllin, was first isolated in a state of purity by Mr. John R. Lewis 
(see Am. Jour. Pharm., xix, page 165,) and shown to be a resin like that 
of jalap. 
