62 



Journal of Applied Microscopy. 



and basic oi- rosanilin hydrochloride or 

 hydrochlorate. 



It is said that the saurefuchsin or 

 fuchsin S is only made by the Badische 

 Anilin und Soda Fabrik, but can be 

 obtained through the agency of 

 Gruebler. 



Congo red, which is sometimes given 

 as a synonym for fuchsin, is an acid 

 variety of the same and similar to the 

 saurefuchsin, though alkaline or neu- 

 tral in aqueous solution; but it has one 

 great difference and one that is of value 

 in clinical microscopy, i. e., its chemical 

 affinity for free acid, it changing to blue 

 if the least trace be present, hence used 

 in testing gastric juice for showing the 

 presence of pepsin or carcinoma of the 

 stomach. And again, we have another 

 closely allied dye to the one just men- 

 tioned, namely benzo-purpurin, which is 

 an acid stain, the B variety being the 

 cheapest and best contrast dye for 

 haematoxylin specimens, and far supe- 

 rior to eosin (red or blue), as it is not 

 affected by clearing agents. Another 

 variety of Benzo-purpurin, 6 B., is very 

 valuable in being a highly sensitive test 

 for HCl. and more sensitive even than 

 Congo-roth or red. 



Here we see the necessity of knowing 

 what variety of Benzo-purpurin to order, 

 for if we should use the B. variety for 

 free HCl. testing, no result would be 

 obtained, and vice versa. 



Squire makes the statement that Dr. 

 Warwick first noticed, that Rose-bengale 

 demonstrates early amyloid. According 

 to Lee (2nd ed.) Rose-bengale is an 

 eosin dye of the bluest known, so can- 

 not be grouped as a rosanilin. Gibbes, 

 prior to 1888, used for amyloid degenera- 

 tion rubin, and obtained excellent 

 results. Here, possibly, lies the reason 

 that other workers cannot succeed in 

 obtaining this reaction. If rubin is 

 understood to be the same as fuchsin S 

 or acid fuchsin, it is different from rose 

 bengale; but is the same as saure- 

 fuchsin, and positively, noted by Heid- 

 enhain in preparing his modification of 

 Ehrlich-Biondi triple stain. Personally, 

 I have dyes bought from Gruebler, 

 Becker of London, Hopkins and Wil- 

 liams, London, Merck, & Shuchardt 

 under the name of rose bengale, rubin 

 S., fuchsin S., saeurefuchsin, and rubin 

 acetate, and have succeeded with none 

 in obtaining this reaction, and I used 

 different cases of amyloid disease and in 

 all stages. But with Becker's rosanilin 

 nitrate I obtained excellent results. 

 Mucin of goblet and mucous cells in 

 vertebrates and invertebrates stains 

 well with basic tar colors, i. e., the 

 hydrochloride or nitrate of rosanilin, 

 commercial fuchsin, Gruebler's neutral 

 fuchsin (n. Unna). These few examples 



will show very well the inexact method 

 of nomenclature in the rosanilin group. 

 Can some worker who has had more 

 experience in one or other variety of 

 this reagent assist in clearing the sub- 

 ject? Let him state the special name 

 and value and if others will follow, we 

 can soon tabulate this dye. The one 

 described is by no means the only one 

 in confusion, for Bismarck brown is con- 

 fused with vesuvin; methyl blue with 

 methylene; Ehrlich Biondi triple dye 

 with the triacid. So much error exists, 

 in the blood stain of Ehrlich-Biondi- 

 Heidenhain, as regards the method of 

 making the solution, each formula call- 

 ing for modified amounts, that it is rare 

 to get an excellent stained slide where 

 the varieties of color are seen equally 

 well. Cabot, in his book on blood, wisely 

 says, "The anilin colors vary so much, 

 that it is rare to get two mixtures that 

 stain just alike, even though made upon 

 the same formula. Each observer must 

 work the details out for himself after 

 learning from some 'show specimen, "^ 

 how a good stain looks." This is true, 

 but let each writer state the correct 

 name of the dye, the firm from whom 

 obtained, and mode of preparation with 

 all particulars, then we niay succeed 

 perhaps more often and be able to verify 

 the research work of others. 

 Chicago, 111. 



References: 



1. Roscoe & Schorlemmer, Chemistry, 

 Organic. 



2. Schultz & Julius, Survey of Organic? 

 Coloring matters. 



3. Napier, Chemistry Applied to Dyeing, 

 etc. 



4. Capron, Blues and Carmines of Indigo. 



5. Benedikt. Coloring matters. 



6. Wagner. Hdbk. of Chem. Techn. 



7. Journ. of Chemistry, etc., etc. 



Agar. 



Some years ago I had occasion to use 

 a great quantity of agar for bacteriologi- 

 cal work, and I tried many experiments 

 in order to find some quick way of pre- 

 paring it and still have it clear, as the 

 filtering processes given in the text- 

 books were a weariness to the flesh. The 

 following method gave extremely satis- 

 factory results: 



The agar — usually for from three to 

 six liter.s — was prepared by cutting into 

 small pieces, soaking until soft, washing" 

 in several waters, and picking out the 

 scraps of foreign substances, of which 

 there are often many. It was then put 

 into the beef tea, which had been prev- 

 iously prepared according to rule, and 

 which contained the peptone and sodium 

 chloride. The whole was boiled in a 

 porcelain-lined saucepan until the agar 

 was dissolved, and during the boilings 



