In this paper, we show that the category of Mackey-complete, separated, topological convex bornological vector spaces and bounded linear maps is a differential category. Such spaces were introduced by Frölicher and Kriegl, where they were called convenient vector spaces. While much of the structure necessary to demonstrate this observation is already contained in Frölicher and Kriegl’s book, we...

Derived varieties were invented by P. Cohn in [4]. Derived varieties of a given type were invented by the authors in [10]. In the paper we deal with the derived variety Vσ of a given variety, by a fixed hypersubstitution σ. We introduce the notion of the dimension of a variety as the cardinality κ of the set of all proper derived varieties of V included in V. We examine dimensions of some varie...

A description is given of a simple, rugged instrument for determining the osmotic pressure developed by a solution of a high polymer. Other small osmometers described previously [1, 2, 3, 4, 5]/ have been, in some respects, too inconvenient to use. Although relatively easy to make, glass osmometers are fragile and may require frequent repairs. Small metal osmometers, in addition to being rugged...

‘The need to justify our beliefs to ourselves and our fellow agents subjects us to norms, and obedience to these norms produces a behavioural pattern that we must detect in others before confidently attributing beliefs to them. But there seems to be no occasion to look for obedience to an additional norm – the commandment to seek the truth. For – to return to the pragmatist doubt with which I b...

A convenient assay for interferons based on reduction of cytopathic effect was developed. The number of manipulations and the lengths of the various incubation steps were reduced to a minimum. The assay is simple to perform and can be completed within 16 h. Moreover, it can be used with various types of cells and a variety of viruses.

A simple apparatus for the preparation of ketene (CH,--C =O) from acetone vapor is described by Ott, Schr6ter, and Packendofff (1). A more rigid and convenient apparatus has been designed and used by the writer (Fig. 1). Pyrex glass used in both the filamentsupport and bulb reduces the possibility of cracking or breaking. The removable filament-support makes it possible to replace the filament ...

A dafe, convenient, portable pipetting device that will accommodate any size pipette is described. A vacuum bulb eliminates the need for external vacuum. Necessary components, fabrication procedures, and operating techniques are given.