On page 187 will be found a letter from Dr. Nichols, of Haverhill, Mass., respecting " burning fluids and the wire gauze lamp." We have but a few words in explanation to say respecting it and the matters upon which it treats. On page 173, in making a few remarks about burning fluids, we said, " there is no fluid so clear and beautiful for domestic artificial illumination as a mixture of turpentine and alcohol distilled together." It should have read, " double-distilled alcohol and turpentine mixed together." As we have furnished many persons with receipt fr mixing these fluids, the error is a singular one. We have repeatedly stated that the common burning fluids should not be used in houses where there are servants or children. We know of two cases of explosions, not of lamps nor cans containing the fluid, but by the fluid. One was by a servant girl, who thought that as paper saturated with oil was excellent for kindling a fire, she would try some of the burning fluid, which must, as she thought, be much better ; she therefore saturated some paper with the fluid, put it in the stove, piled on some chips and charcoal, and then ignited the paper with a match, when lo, to her astonishment, off went the kindling pile like powder, the covers were thrown ff the stove, and chips and charcoal scattered over the floor. The other case differed only from this in using some shavings for kindling a fire which had been saturated with spilt fluid, and were used in ignorance of this fact. No one was hurt, but these cases are positive proof of the danger of having such a fluid about. We have the word of Mr. Newell, and also that of Dr. Jackson, to the effect that the latter had nothing to do either by consultation or otherwise, with the holes in the cap of New-ell's lamp. We therefore rely on this personal testimony as positive. We do not know what kind of fluids they sell in Boston, but we know that a burning fluid (alcohol and turpentine mixture) has been sold here under the deceptive character of rosin oila safety fluid. Prof. B. Silliman, of Yale College, in a litter to the " Boston Traveller," which has been extensively copied in other papers, asserts that the danger of explosions in lamps burning alcohol and turpentine mixtures, " may be entirely avoided by the use of wire gauze protectors, which have been recently introduced." These quoted words are from the letter. He also adds, " I have no interest whatever in the invention." The subject of burning fluids and "safety fluid lamps," has excited a most interesting and explosive state of feeling among some of our New England professors of chemistry. The letter of Prof. Silliman is used as a tremendous truncheon of high authorative endorse- ment of Newell's wire gauze lamp, so are the certificates of Drs. Jackson and Hayes, of Boston, also that of Prof. Cleveland, of Bowdoin College, Maine. The lamp as made by Newell & Co., with the wire gauze protector, is the best we have seen ; this is all we can say of the matter; we can only speak ofthat with which we are acquainted, and il it is a re-invention, the fact of Jennings' previous claim was, we believe, unknown to the re-inventor, whose name, we humbly think, has unjustly, for his honor, been kept from the public. This subject has received all the attention we can devote to it, at least for some time.