April 190?.] 



221 



Timbers. 



assisted by the use of Swedish Patent No. 2939, he succeeded during that year in the 

 performance of technical trials on a large scale, and in 1875 he obtained a directly 

 prepared solution of di-sulphite such as he had previously obtained from a calcium 

 carbonate. At that time he obtained the action of pure calcium bi-sulphite on 

 wood, preparing the salt by running sulphurous gas over pieces of carbonate of 

 calcium. Af tevwards he constructed a tower for making the bi-sulphite of calcium. 

 This method seems to have been considerably followed., and in 1S66 a sulphite mill 

 was built in America on Mitscherlich's Hues, and according to a report from 

 Thilmany (1894), the Mitscherlich process had been favourably adopted, and to 

 such an extent that about that time there were forty boilers in operation in the 

 United States and four in Canada ; and the total yearly product in the States at 

 that time was about 50,000 tons, On turning to Muspratt's technical handbook of 

 that time, Mitscherlich is mentioned as the inventor of sulphite cellulose. Without 

 committing himself to Stohmann, whose opinion has been freely quoted, it is 

 significant that this authority mentions Tilghman and others, but merely to show 

 that their experiments, as compared with Mitscherlich's success, had no weight, 

 since they were not performed in a practical manner, and because they gained no 

 technical success. 



Stohmann, however, was subsequently reminded that the earliest' edition of 

 Muspratt contained no mention of Mitscherlich, although his mill in Munden was then 

 in secret operation. Prof. Fittica, on this subject, summarises his opinion in these 

 words : " Tilghman used the sulphurous acid, or he intended to use the same ; but 

 he did not use the sour calcium salt of the acid, and did not prepare or use the same 

 in its pure state, in which conditiou only is it practicable for that purpose. For 

 this reason, Tilghman had to discontinue, after ten years of restless activity." 

 Ekmann's magnesium sulphite, however, undoubtedly and finally proved to be a 

 suitable preparation. Several other experimenters also failed to comprehend the 

 action of the temperature, so that also in this respect we must give Mitscerlieh the 

 credit due to him. As might have been expected, Prof. Fittica's contentions 

 provoked very considerable criticisms, and some rather severe comments, and return- 

 ing to the fray, Fittica says in 1901 : " In my history, in the manufacturing of sulphite 

 stuff, I mentioned especially that it was Tilghman, besides others, who had already 

 undertaken to make experiments to make sulphite fibre by means of sulphurous 

 acids, but that it was Mitscerlieh who provided a practical foundation to these 

 experiments, and he must be called the first inventor in case the question arises 

 as to a really practical invention. The germs of the idea of a new invention, a new 

 principal, a new law, a new conception of the universe only take root gradually. 

 Each idea has its forerunner, and these forerunners are present in every direction 

 .... The person, however, who forms these ideas in the practical shape must be 

 considered the inventor, because his forerunners have not performed a technical 

 realisation. . . . Consequently," adds Prof. Fattica, " I repeat that it was 

 Tilghman, besides others, who furnished the idea of manufacturing sulphite fibre, 

 but it was Mitscherlich who added hand and foot to the practice, and, therefore, 

 must be called the real technical inventor of the sulphite cellulose fabrication." 

 Quite recently, Prof. E. Kirschner added a very important contribution to this 

 controversy, and wrote that Ekmann, in Bergvik, Sweden, produced regularly large 

 quantities of the valued sulphite pulp in 1874. That was long before Mitscherlich, 

 and Prof. Kirschner adds that Fittica did not apparently seem to be aware that 

 magnesium bi-sulphite, and also sodium and potassium compounds, produce not 

 only the same effects in the sulphite process as calcium bi-sulphite, but would be 

 even preferable to the latter, were it not for the higher cost of the bases contained 

 in the former. Prof. Kirschner went at some length to substantiate his arguments 

 by giving interesting chemical details, and went on to observe that " seeing that 



