This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1908 Excerpt: ...intention in general seems to be that the boiling points are the temperatures at which complete distillation occurs. For example Benzin is stated as having a boiling point of 45 to 00 C., meaning presumably that it all distills between these temperatures. Since the pharmacopoeial chemicals are admittedly not pure, this ...
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This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1908 Excerpt: ...intention in general seems to be that the boiling points are the temperatures at which complete distillation occurs. For example Benzin is stated as having a boiling point of 45 to 00 C., meaning presumably that it all distills between these temperatures. Since the pharmacopoeial chemicals are admittedly not pure, this style of boiling point should be adopted throughout the text; that is an upper and lower limit should always be given. Such is not always the case at present. A method of determining boiling points that has been found reliable in the hands of many chemists and applied to many chemicals may be outlined here. It is suggested as a good basis for a general method to be used in connection with the next revision of the Pharmacopoeia. Select a side-arm distilling-flask (a fractionating-ilask) with plain neck (not bulbed), having the side-arm about two inches above the bulb part of the flask. Fill the flask approximately two-thirds full of the material under examination and insert the thermometer so that the top of the mercury bulb is about half an inch below the side-arm of the flask. This thermometer should of course be selected for small thin bulb so that it is easily affected by small changes in temperature and quickly comes to the correct readings. After connecting with a suitable condenser heat the flask carefully by means of a small flame held in the hand and passed to and fro under the bare bulb of the flask. The flame should generally be only about an inch long and is best when semi-luminous or luminous. This may be obtained by partly shutting off the air on a small Bunsen burner and turning the gas low. Sometimes it is advisable even to black the bottom of the flask with the flame as the heat is better distributed in this way. Continue to h...
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Add this copy of Pharmaceutical Review, Volume 26... to cart. $57.56, good condition, Sold by Bonita rated 4.0 out of 5 stars, ships from Newport Coast, CA, UNITED STATES, published 2012 by Nabu Press.
